Posts Tagged ‘uncertainty management’
Good (Late) News from the SEC
We Missed It a Few Months Ago
On the front page of the The ‘Money & Investing’ section of today’s edition of The Wall Street Journal, there is an article entitled, At SEC a Scholar Who Saw It Coming.
The article is about Henry Hu, who manages the newly-formed Risk, Strategy and Financial Innovation division at the SEC.
Though he sounds like a good guy, we don’t know much about Mr. Hu, but that’s not why we’re writing. It also mentions that in November, Mr. Wu hired Richard Bookstaber to lead staff training and data analysis, and that is a good thing. (The print version incorrectly identifies him as David Bookstaber.)
If you haven’t heard of Mr. Bookstaber, he has much knowledge and much experience working at large trading firms and hedge funds. In fact, he takes “partial credit” for a few of the past crises, including the Crash of 1987.
Mr. Bookstaber is also the author of the 2007 book, A Demon of Our Own Design, which discusses those crises, his roles in them, as well as his approach to risk (and uncertainty) management. We highly recommend the book to anyone in the financial services industry and within particular roles in other industries, too. For example, we recently recommended it to the chief of security at a large, U.S. based, multinational that operates factories and plants throughout the world.
In the book, Mr. Bookstaber makes the excellent point that overly-rigid or overly-complex risk monitoring and safety systems can actually increase the probability of failure and the loss given failure and discusses it both within and outside of financial services. (Recently, we made similar points in our analysis of intelligence failures and bad information system design.)
Besides reading the book, we also encourage our readers to visit Mr. Bookstaber’s blog, especially to read his testimony before Congress – the links in the right-hand column). It is well-written and not overly-technical.
Regarding risk and uncertainty management, Mr. Bookstaber makes points similar to ours, with the main intersection being that not every crisis is predictable, but thoughtfulness and contingency analysis goes a long way to mitigating crises. In fact, preparing (rather) general responses to possible, specific crises can prepare one for completely unknown ones, too. (See our essay on uncertainty management and almost any of our posts categorized as uncertainty or risk. By the way, we really like our post with the tongue-in-cheek title, The Role for Survivalists and Depressives in Uncertainty Management, because we think that personality traits like skepticism and pessimism are under-weighted and under-valued in most risk management hiring process.)
The best that we can tell, we tend to place more emphasis on stress-testing and scenario analysis than he does, but that’s because we think that imagination, like skepticism, is under-estimated, too.
One topic where we do disagree is his insistence that everyone (that matters) understands the limitations of the use of normal distributions in risk measures like VaR (Value at Risk). To explain, 2e’ll try to be concise but thorough but will err on the side of brevity.
It is well-known – though not wholly-agreed-upon – that assuming normality (or log-normality) mis-specifies models of returns, and we think that many ‘quants’ do know that, but they use those assumptions nonetheless, and that’s for a few reasons:
- There is no other choice, or no other tractable choice.
- Depending upon the context, it may not matter much.
- Ease of calculation and effort. (This is different than (1).)
- As a way to reduce measures of risk characteristics.
- Ease of communication to others.
We are very sympathetic to the first two reasons, and being somewhat lazy, we are also sympathetic to the third. However, the fourth reason hints at cynicism and greed and, depending upon who is using the measure, it can be very destructive. Also, if such assumptions are used for opportunistic reasons, that can indicate the traditional weakness of risk management vis-a-vis revenue-generating departments.
The fifth reason hints that maybe – just maybe – not everyone understands the calculations and assumptions and their flaws.
We have dealt with very high-level managers at very large firms who are quite ignorant of the basic characteristics of normal distributions. To their credit, a few were quite willing to admit as much. (They are the least harmful of the bunch.) But given those experiences, it is difficult to believe that most board directors understand the arithmetic; so, it is difficult to accept that all senior managers (at such firms) understand the calculations; so, it is difficult to believe that all other managers, traders, salesmen, and investors are knowledgeable and well-informed. (And, boy, could we tell you stories!) The fact that, as Mr. Bookstaber points out in his testimony, such topics appear in textbooks is a non sequitur.
When one combines cynicism with miscommunication – whether purposeful or not – there’s a good chance that the organization is bearing more uncertainty and risk that it imagines or measures, and that’s not good. So, that fact that “everyone knows” something – even if it that something is true – doesn’t mean that it’s not abused. For example, pick any vice that every “knows” is wrong but folks do it anyway. The abuse of illegal drugs and obesity are two analogous examples. (Oh, by the way, government regulation doesn’t seem to help much there, either.)
Finally – almost – these last two issues hint at incentive problems – both moral hazard and adverse selection – that exist within firms, and we’ve written extensively about that, too, e.g., Incentives and the Financial Crisis and many more.
In sum, while we have never met Mr. Bookstaber and likely never will, we are encouraged to see the SEC hire such a knowledgeable and wise person. We wish him the best in his new role. (We only wish that we would have done so a few months earlier.)
An Out-of-this-World Analogy
The physicist Michio Kaku has a short opinion column in Thursday’s edition of The Wall Street Journal: Jupiter Gets a Black Eye. In it, he mentions the Jupiter’s recent collision with a comet or asteroid – it created a fireball as big as the earth – and then discusses our planet’s vulnerability to relatively large and unknown space objects.
We like the column because it provides a nice – though not complete – analog of risk management at financial institutions. Actually, this is one instance where the government may do it better. (Wow, we can’t believe that we wrote such a sentence!)
It’s likely that anyone with a web browser and the sophistication to access our site knows that there is a danger that satellites and space debris within earth’s orbit may crash down upon them. For the most part, those risks are relatively well-understood. Generally, their effect would be like an idiosyncratic financial risk to, say, a particular firm. All else equal, the satellite or its pieces would hit a particular small region and have limited impact and implications; possibly, disastrous to a few, but probably not to very many. Of course, there is always a possibility that such a natural (or nearly natural) disaster could start a chain-reaction and have far-ranging political, economics, and social implications beyond that of small, geographically-isolated incident.
Outside of the earth’s orbit – but within the solar system – are about 5,000 near-earth objects (NEOs) that have also been categorized. These are items reside within the solar system and orbit the sun, but their orbits may intersect with the earth’s orbit and eventually intersect with the earth. Unfortunately, solar orbits not all concentric circles or elipses.
Some of the NEOs are small – like man-made satellites in solar orbit – but others are huge and could cause serious damage if not complete annihilation of the earth (and its inhabitants). Just look at the surface of the moon for some extraterrestrial evidence. The earth has been hit by such items, too, and they’ve been very destructive, e.g., the Tunguska event. Impacts of smaller items could be viewed as idiosyncratic risks, whereas the larger ones – like giant volcanoes that could cover the earth in dust – would be more like systemic risks that affect everyone. Overall, it seems that generally, these near-earth objects are sufficiently well-understood that they can be modeled with a sufficient degree of (predictive) confidence. (That if something bad is going to happen, we’ll likely know about it.)
The last category of threats involves extrasolar ones. Their number, size, and other characteristics are unknown, e.g., whether they have regular or irregular orbits (or trajectories). They are things things that could crash into the solar system and and earth without warning. Those threats create plenty of uncertainty, but no risk because there is no way to measure them (and risk is nothing more than measurable uncertainty).
That’s not the biggest difference between threats from space and financial calamities. Despite what bad modelers (and bad risk managers (and bad chief executives)) may tell you, there is a substantial amount of immeasurable uncertainty in trading and investing activities, too. The losses associated with either type of uncertainty can be individually or collectively devastating.
No, the biggest difference is that with enough monitoring devices, it is possible to categorize those physical threats and their causes and assign probabilities to them. We doubt that it will ever be the case with the countervailing forces of greed and fear and their psychological and emotion causes. That doesn’t mean that uncertainty management–as it pertains to the financial markets – is a hopeless cause: only that one should be careful and aware that unpredicted and unforeseen and unimagined events can indeed happen.
Finally, note that like financial markets and the recent crisis, solutions to potential threats could be worse than the threat itself. Mr. Kaku mentions Hollywood’s solution, à la Armageddon, of attempting to explode a large comet into a bunch of small pieces would make things worse. That would be like hitting the earth with a shotgun blast, rather than with a rifle – possibly systematizing a hard, but idiosyncratic risk. That wouldn’t be fun.
Of Rats and Men
We are in the midst of writing a rather long post on the similarities between teenage girls with low blood sugar and daily and intra-day changes in equity prices. Namely, one can see huge swings in behavior, attitudes, and mood caused by seemingly very minor underlying events, e.g., “she looked at me the wrong way.” The “she” in this case being an eight-year-old sister.
However, we couldn’t complete that post because another thought keeps diverting our (limited) attention from it.
We were driving with the Chairman earlier today when she mentioned that the neighboring county was holding its fair, and that it was one of the largest county fairs in the state. She went on to explain whenever she thought of fairs and state fairs she would think of the book, Charlotte’s Web. (We’ve never read it because it was a girls’ book in our youth, and we did not read girls’ books: not then, not now.) As she explained, she particularly liked the chapter in which Wilbur the Pig goes to the State Fair, and Templeton the Rat tags along in the pig’s cage.
As she explained it, when the rat investigated his new surroundings, he thought that he had reached paradise. He was amazed at the wealth of delicacies that he could find on the ground – probably things like popcorn and corn dogs and ice cream cones and maybe deep-fried Snickers bars.
Upon hearing that, a question came immediately to mind: so, did he stay there?
See, we could imagine the rat believing that he had reached the proverbial land of milk and honey – in this case, half-eaten corn dogs and ice cream cones as far as the eye could see. It would seem to be an almost limitless supply. Except, except for the fact that state fairs only last for a week or two.
If he decided to stay at the fairgrounds after his swinish friend returned to the farm – if that’s where the pig went – then it could easily seem to have been the best decision of his life – for a week or two. Until the cleanup crews came and swept the refuse away, and until he began to face the following 50 weeks of deprivation and hunger.
Despite its completely deterministic and cyclical nature, the “great bust” or ” great depression” or “great famine” or whatever phrase he would have used to described the closing of the fair, would have seemed completely unpredictable and random. Templeton and his other rodent friends, could easily ask, “who could have ever predicted it? or “how could it be my fault?” Of course, it could be that things that seem to be too good to be true, often are.
Now, we are not comparing the recent (and ongoing) financial crisis with our imagined scenario of Templeton the Rat’s life. In our mind, economic crises tend to have endogenous causes, i.e., they erupt from within the system – not from an external source like a natural disaster or in this case, the predictable end of a two-week fair.
However, we do think the scenario is instructive. To Templeton the Rat, the destruction of his new environment would have seemed like a unpredictable tsunami. He wouldn’t have known when or if the good times – the fair – would end, and he wouldn’t have known what he didn’t know, i.e., very important characteristics of his environment.
It’s that aspect that is instructive, and it’s why we think that trading and investing firms should increase the scope of their risk management functions to the broader function of uncertainty management. “Uncertainty” includes the explicit realization that (1) not all randomness is measurable risk and (2) seemingly incomprehensible and unconsidered bad things can happen.
Note however, that just because such things are (currently) incomprehensible doesn’t mean that (i) that can’t be protected against and (ii) they can’t eventually be imagined through creativity and reason. The former is true because adequate protection against known harms can also protect against unknown ones; putting your house on stilts protects against known seasonal flooding and unknown tsunamis. The latter is true because that is the nature of human progress and the expansion of knowledge through experimentation and contemplation: think of humanity’s relatively recent discoveries of bacteria and viruses. Interested parties looking for more should read our essay, Uncertainty Management or our tongue-in-cheek post, The Role for Survivalists and Depressives in Uncertainty Management.
Finally, please note that we chose our title carefully. It’s a play on the line from the Robert Burns poem, To a Mouse, On Turning Her Up in Her Nest with the Plough. We Anglicize the line as: “the best laid plans of mice and men often go awry and leave us nothing but grief and pain.” We’d add that less thoughtful plans often don’t turn out that well. Read the entire poem on our quotes page.
Computer Problems
Despite a few interesting weeks of activity in the world, we have not posted much lately. That’s because we’ve had a variety of computer problems at world headquarters. We woke up last Wednesday morning to a BSoD or Blue Screen of Death on our desktop/network server. Our Western Digital Raptor hard drive had failed. It was unbootable and inaccessible.
We replaced it the following day with a bigger and slightly faster VelociRaptor.
At the same time, we decided to upgrade from Windows XP (Media Center) to Vista Ultimate. As we wrote a few months in Walt Mossberg is Wrong, Again, in our experience Vista tends to be more stable and faster than Windows XP. That’s not the sentiment (or should it be sediment?) that you’d get from dear old Walt or a variety of other writers or bloggers, but skepticism is in order when reading “stuff” on the web (except, here, of course, where we have enough skepticism for ourselves and everyone who visits).
We must admit to making a mistake when we purchased the new operating system; we bought the 64-bit version instead of the 32-bit version that we wanted. When it arrived and we noticed the “64”, we figured we’d give it a try, and we have been very pleasantly surprised. Perhaps it’s the new hard drive, but the 64-bit version is fast. It is stable, and it has run every 32-bit application that we have loaded.
Many bloggers and writers have complained about the lack of 64-bit drivers, but many of those complaints seem to be several years old, i.e., from 2006 or so. So far, we’ve had no problems installing any of our hardware, including an older USB, HDTV tuner; an Epson R1900 printer, and a Canon MP830 multifunction device. We have one rather esoteric piece of equipment left to install – a Graphtec Robo Pro 5000 – but based upon what we read on-line (oh dear) we think it will work, too.
Vista 64-bit provides a few other advantages over 32-bit Windows, too. We’re finally able to use all 6GB of our installed memory, so there is less hard-drive caching, and 64-bit operating systems are supposedly less susceptible to 32-bit viruses. (We have no personal experience with that claim, but it makes sense to us.)
Despite being disruptive and time-consuming, the crash wasn’t a total loss. Our systems are stronger and better than they were. (Hah! Don’t you wish the same were true of the financial system!) After almost of week of use, we only wish we had made the same “mistake” during the recent purchase our two portable workstations.
Speaking of which, unfortunately, the desktop’s hard drive failure was only 0ne-half of our hard drive problems.
For a few weeks, our M4400 laptop has been behaving badly with frequent, unexplained crashes. After we finished repairing the desktop, the condition of laptop’s hard drive worsened; however, unlike the desktop drive, the laptop drive isn’t completely dead, but it quite a nuisance.
Now that the replacement hard drive has arrived from Dell, we’ll spend the rest of the day reinstalling our programs. We should be back to posting our viewpoints either tonight or tomorrow.
By the way, we’re quite happy to have installed Norton 360 backup. It worked automatically and well on both machines, and spared us a lot of misery and irritation and time and money.
Incentives and the Financial Crisis
There’s an excellent opinion column in yesterday’s (May 28) edition of The Wall Street Journal. It is Crazy Compensation and the Crisis by Alan S. Blinder.
Why do we write that it is “excellent” the dear reader may ask?
Well, for the obvious (and self-serving) reason that we have been writing the same critiques on these pages for much of the past year or so.
Mr. Blinder identifies several problems that created the potential for the crisis and its subsequent realization.1 We will categorize the problems that he identifies as:
- Wrong legal form/organization structure for some firms,
- Incompetent boards, and
- Lax controls and poorly-designed incentives.
He treats them in a different order than we list them; we’re going from top-to-bottom, which is consistent with Our Control Framework. Clearly, the three categories are related. For example, see our popular post, SOX’s Roles in the Financial Crisis of ‘08, which hits on all three topics, and criticizes government regulation to boot. In our mind, they all provide evidence of the fallen nature of man. (We’re not complaining about that nature. We accept it in ourself and, to a lesser extent, in others. We’re only trying to profit from it.)
Wrong Legal Form/Organization Structure
We wrote about this on September 26, 2008, when we asked Will Investment Banks Go the Way of the Dinosaur? In that post we speculated that partnerships may make a comeback because “They provide control mechanisms and levels of oversight and scrutiny that seem difficult to duplicate in public corporations.”
Mr. Blinder made explicit what was implicit in our post: the difference between one’s level of risk-taking when managing OPM (Other People’s Money) versus what he refers to as MOM (My Own Money), or one’s own money.2 Those facing unlimited personal losses tend to be more conservative than those with limited losses.
In January, in a critique of The Wall Street Journal’s editorial board, What Did They Expect?, we wrote, “We also disagree with their [the editorial board’s] assessment that “compensation levels are a business judgment made under the pressure of competition.” That might be true if the firms were partnerships or otherwise privately-owned, there was no agency costs, and there was no self-dealing, i.e., the firms were run by independent and knowledgeable boards.”
But with D & O (directors’ and officers’) insurance, the limited downside of losses severely decompresses that so-called “pressure of competition” for boards. Moreover, shareholders of bank holding companies (and other corporations, too) implicitly permitted managers to take greater risks. In fact, Mr. Blinder seems unwilling to blame shareholders when almost every stockholder was quite capable of selling their stakes. So, we have no sympathy for folks who wanted the opportunity for large gains without bearing potential liabilities if the firm.3
Incompetent Boards
While “Incompetent Boards,” may seem a bit harsh to some, we think that it is milder than many alternative and equally fair characterizations, and there is no shortage of evidence. See Directors Are Faulted at Home Loan Banks for example.
Regular readers will note that we often ask whether a party is ignorant or cynical, and in this case we’d prefer to believe that many directors were unqualified to understand the uncertainties and risks associated with investing and trading, particularly with derivatives and other structured products. In some way, that seems more “decent” and ethical than the alternative: the cynical and devious behavior of understanding the potential for loss but ignoring it due to one’s own limited liability.4
For example, with the recent changes in the composition its board, Citicorp has as much as admitted the lack of requisite expertise of its past board. We’ve written about these topics in the past, particularly in: The Failure of Boards to Direct, The Seventy-Year-Old Teenager, When the Going Gets Tough…Quit, and Idiosyncratic and Concentration Risk, Again. (Update: within hours of publishing this post, B of A announced that one of its directors was resigning: see BofA Says Sloan Quits Board Seat. There was much speculation that it was due to government pressure.)
Those (generally weak and) incompetent boards permitted senior managers to maintain the lax controls and poorly-designed incentives about which we have often written, and here is a summary.
Lax Controls and Poorly-designed Incentives
As Mr. Blinder notes, poorly-designed incentives – primarily via compensation schemes – led to ex post “excessive” risk-taking. We write ex post as in 20 – 20 hindsight as in “there are massive losses, so someone must have done something wrong,” but, in fact, we’re note using that logic. Instead, we note that there was no shortage of individuals warning about the risk and uncertainties ex ante.
Unfortunately, many such folks were dismissed either figuratively or literally by senior managements. (It’s analogous to the SEC’s treatment of Harry Markopolos. See Cassandra, the SEC and Mr. Madoff.) Moreover, it is consistent with the perspective that risk managers generate no revenue and are costs to be minimized (and often voices to be ignored).
So, yes, traders (and their managers) took gambles because they bore (or thought they bore) limited downside risk but instead focused on the potential for substantial (enormous) compensation rewards, but lax controls and ignorance are bigger issues than just poorly-designed compensation schemes because said traders were allowed to take those gambles with OPM.
That lack of control has many facets, but can be summarized in terms of as greed, ignorance, and insecurity. Notice that, of course, those emotions/human conditions are always present, but precisely the job of senior managers (and boards and owners) to design schemes and mechanisms that take those as given and mitigate them – rather than exacerbate them – while the organization attempts to achieve its objective. (We’ll have more to say about that below.)
Ignorance, and its relative, insecurity, were crucial to the control failures. Few folks are willing to admit that something is immeasurable or nearly impossible to quantify because that can be turned-around and used against them as a personal short-coming:, e.g., “that’s just because he doesn’t know enough.” So, personal insecurity and incentives often induce employees to “take the easy way out” and endorse or embrace a simplistic and inapplicable valuation or risk model.
For example, in early November, we wrote The Understatement of the Year! in response to an article in The Wall Street Journal entitled, Behind AIG’s Fall, Risk Models Failed to Pass Real-World Test. While the entire post is relevant to this discussion, we particularly like this extended excerpt:
The problem, dear reader, is that few senior managers (and almost no board members) understand the valuation and risk models used for securitizations, and many of the traders, consultants, and analysts who wield such tools often suffer from, what one may call, “framing” issues; we don’t mean that aspect of home construction despite its recent relevance.
We mean that if one’s only tool is a hammer, then lots of things look like nails. The metaphoric hammer may be an intangible Visual Basic or “C” programming algorithm, but the point remains the same; it’s just harder for senior management to see what one is pounding in their cubicle, office, or trading-floor seat.
To be sure, if anyone within most of the larger firms would have complained of the systematic risk — and how everything could go bad all at once — and the inapplicability of the standard models, which generally don’t permit such events, then that person most certainly would have been told that they don’t know what they’re talking about. Possibly, that they are unsophisticated or too negative.
Earlier this week in Uncertainty: In God We Trust, we noted “Too many senior managers neglected their responsibilities and permitted the substitution of calculations for thoughts.” That as been a pet peeve of ours for quite some time and is the antithesis of our motto: thought before calculation. See The Difference Between Risk and Uncertainty for a relatively short exposition of the issues.
Those dysfunctional behaviors were not necessarily malicious or anti-social by intent, but does that matter, especially since thoughtful design of control mechanisms could have inhibited them? See Principles Lost and More, in which we contrast Saint Thomas More’s actions in the 16th century with the more recent actions of many less holy individuals prior to and during the Financial Crisis; there’s a reason he’s a Saint and we’re not.
We’ve written much, much more on this topic, but as we noted in The Problem of Induction, we’re not underestimating the difficulty of the problems faced by traders, structurers, and risk managers. In fact, if anything, we’re overly conservative by stating that not all uncertainties and losses can be quantified and the problems are much more difficult than some suppose and/or communicate.
What To Do?
Unfortunately, Mr. Blinder notices that there has been little-to-no structural change in corporate governance. He attributes the differences in markets – the illiquidity or lack of trading – to fear, rather than to newly designed or revised controls, and that seems about right to us. As we noted last month in Learning the Difference Between Risk and Uncertainty, or not, job descriptions and hiring requirements for many trading and risk management positions don’t seem to have changed; so, it doesn’t seem the firms have “re-engineered” or redesigned their operations or controls.
In October, we wrote a tongue-in-cheek post about The Role for Survivalists and Depressives in Uncertainty Management, but in all seriousness, hiring such personalities and listening to them is one way to compensate for flawed risk models.
To be fair, we have read about a few firms, like UBS, that have changed their compensation schemes to include features like clawbacks. See Clawbacks: the Good, the Bad, and the Ugly and Incentives at UBS and in General. However, it is not clear whether such changes have been thoughtfully managed. As we mentioned in Business Schools, Incentives, Uncertainty, and the Financial Crisis, it seems that little has been done because: (1) such incentive problems are very challenging to solve, and (2) universities don’t do a particularly good job of training business students to solve them. (Of course, for the right fee, we would be glad to help.)
So what to do?
Mr. Blinder calls for change, but doesn’t exactly explain how or what.
We’ve made several recommendations in past, including this post from early October: Eliminate Proprietary Trading at Insured Institutions. Everything in it – and there’s a lot – holds up well, and we’ve not heard a compelling argument against such a ban. As we wrote back then:
We’re completely for the free-market—more so than most bank managers — but until such institutions forsake their government insurance, we’ll insist that they have an obligation to the citizenry — through the government — to behave in a responsible, low risk manner. If that generates lower returns for them on average, then so be it. That’s the nature of the risk-return spectrum and their legal and fiduciary responsibilities…
We think that such a ban is feasible and would substantially mitigate many of the risks that those banks by eliminating the (socially) undesirable behavior.
Now, that (maximum) risk-seeking behavior is not universally undesirable, but it is within subsidized institutions. We’re all for permitting “prop” structurers and traders to operate in unregulated partnerships and hedge funds, and wish such organizations the best of luck.
P.S. Although this post is rife with links, we’ve written much, much more about the topics of risk management, incentives, and the crisis. Feel free to peruse the archives, and let us know if we’re wrong about anything – other than a few predictions.
P.P.S. As posted, this is rather long, and we’ll likely revise it in the near future as we discover typos, etc.
- Note that with a bit of extremely good luck, the crisis could have been delayed or mitigated if not altogether avoided. ↩
- We wrote possibly our briefest post ever last June on a similar topic: Fools and O.P.M. ↩
- Non-executive, employee-owners with restricted stock are exceptions, and should be treated separately and more sympathetically. ↩
- See Luke 12:41 — 48 for the Parable of the Faithful Servant, which we reference in Which Is More Egregious? Jesus distinguishes between the deviously cynical and the ignorant, too. ↩
Uncertainty: In God We Trust
Mary Anastasia O’Grady has a good interview with Richard Fisher, the president of the Dallas Federal Reserve, in this Saturday’s edition of The Wall Street Journal. It is called “Don’t Monetize the Debt”.
Regular visitors of our site, who are sympathetic to our criticisms of the Fed; elected and appointed government officials; and financial regulators, will find much with which to agree.
We’re writing today to mention a few parts that are directly related to our site. First, per our motto in the header, Thought before Calculation, Ms. O’Grady writes:
And finally, he says, there was the ‘mathematization’ of risk.” Institutions were “building risk models” and relying heavily on “quant jocks” when “in the end there can be no substitute for good judgment.”
We’re not averse to mathematical models, and don’t mind getting paid to develop, analyze, or validate them, but we do agree with Mr. Fisher’s criticism. It must be done thoughtfully. Too many senior managers neglected their responsibilities and permitted the substitution of calculations for thoughts. That being said,we think that it is necessary to add that even the best judgment doesn’t assure favorable outcomes. That, unfortunately, is the nature of uncertainty, which we’ve written about any number of times.
Secondly, the penultimate paragraph describes a painting by Antonio De Simone of a ship in a storm. According to the article, Mr. Fisher has owned it for thirty years.
In the final paragraph, Mr. Fisher is quoted as saying “no mathematical model can steer you through the kind of seas in that picture there. In the end someone has the wheel…On monetary policy it’s the Federal Reserve.”
As the reader can hopefully see for him or herself, we have an image of a similar painting in our header: Rembrandt’s Storm on the Sea of Galilee.
We prefer the helmsman on that boat to the quite fallible men and women at the Fed, who – as we see it – are trying too hard to “steer” the economy.
Perhaps others considered similar analogues when the nation’s official motto became “In God We Trust.” Moreover, we hope that each time they notice it on our paper currency and coins, our representatives and agents are reminded of the inherent uncertainty that they face – be it natural or man-made.
The Difference Between Risk and Uncertainty
Recently, we’ve noticed a substantial number of visits referred by search engines from folks trying to understand the difference between risk and uncertainty. In fact, we have a post from April 20, with the tongue-in-cheek title of Learning the Difference Between Risk and Uncertainty, or not.
In that post, we criticize financial firms because they don’t seem to have changed their uncertainty management tactics or methodologies despite the market upheavals and shocks of the past few years. In fact, they still refer to the field as “risk management.”
However, for those looking for something a bit less verbose – but only a bit – we offer the following italicized distinction, which we’ve excerpted from that post.
The following paragraph is repetitive, but reading different phrases that have the same meaning is often the easiest way to learn. That’s why many students learn better in lectures than by solely reading a textbook; the concepts are usually mentioned and presented in a variety of ways in class, whereas often the textbooks strive for parsimony of exposition.1
As usual, we point new readers to our essay, Uncertainty Management, which details our perspective and philosophy on these issues… The main point is that not all uncertainty is measurable, i.e., that measurable uncertainty, or risk, is a proper subset of uncertainty and unknowing. (In other words, specific mathematical conditions must be met for uncertainty to be risk. So, uncertainty is a more general term, i.e., all risk involves uncertainty, but not everything that is uncertain is risky because not all uncertainty is measurable, which, again, has a specific mathematical definition that we don’t care to mention.)
The above definition of risk as quantifiable uncertainty is due to Frank Knight, who developed it in the early-to-mid 20th century.
Uncertain phenomena are often modeled as risky events. While there are a host of other mistakes that one can make in the modeling process, a huge specification error is made when the phenomenon is uncertain and immeasurable, but it is treated as being measurable. That’s especially bad in financial and economic settings because such modeling errors tend to reduce or eliminate the modeled – but not the real – chances of really bad things happening.
To be a bit more precise, note that for some uncertain phenomena, a probability distribution will not exist.
For others, a distribution may exist, but its moments – which one may grossly think of as its common statistics – may not. For example, there are mathematical functions that are probability distributions, but which have no mean or variance (so no standard deviation, either). Many of them look a lot like Normal distribution and density functions – i.e., they have a familiar bell shape like a Normal density – but their “tails” are “too fat,” and extreme events are hundreds or thousands or millions of times more likely than with a Normal distribution. That difference in frequencies of outlying events is why parameters like the expected value and standard deviation don’t exist.2
The problem in real life is that unless one is playing a structured game of chance, one’s never quite certain whether something is uncertain but not risky, or whether it can indeed be quantified.
Regular readers know that we often cite (1) St. James’ admonition in his only epistle that one is like a “puff of smoke,” in the sense that they and their welfare are temporary, ephemeral, and uncertain; and (2) the Problem of Induction, which notes that regardless of the time series of observations, one can never be quite sure of the underlying random process.
That’s why we gave two subtitles to our essay Uncertainty Management: (1) ignoramus et ignorabimus , which means “we do not know and will not know,” and (2) How Trading is Like Playing in a Culvert on a Hot, Sunny, Summer Day, although “trading” can be generalized to any number of activities, including many social ones where, obviously, behavior and sometimes panic come into play.
Copyright © 2009 Spero Consulting.
Footnotes:
- Depending upon one’s knowledge base, which can be thought of as one’s understanding of words, trying to understand a concept is like looking through a semi-transparent cube to view the underlying idea. The greater one’s knowledge, the less opaque are the cube’s sides. Indeed, depending upon one’s background, approaching from different sides or angles may permit better or worse views of the idea. ↩
- Basically, when one tries to add the products of the frequencies and the potential values, the sum becomes infinitely large and can’t be defined. ↩
Saint James and the Fragility of Life
When we criticize risk management and discuss our take on Uncertainty Management (our essay is subtitled, “How Trading is Like Playing in a Culvert on a Hot, Sunny, Summer Day”) we often cite our favorite quote from St. James’ only Epistle:
Come now, you who say, “Today or tomorrow we shall go into such and such a town, spend a year there doing business, and make a profit”—
you have no idea what your life will be like tomorrow. You are a puff of smoke that appears briefly and then disappears.
Instead you should say, “If the Lord wills it, we shall live to do this or that”
It captures the notion that not all randomness is measurable.
That quote came immediately to mind when we heard of the circumstances of actress Natasha Richardson’s tragic and untimely death.
How many times in sports and in cars – and even crossing the street, especially in front of Port Authority buses – have we taken chances greater than those found in a beginners’ ski lesson?
“There but by the grace of God go I.” We don’t think that thought is inconsistent with our earlier post on freewill.
May God rest her soul and bring peace to her family, her husband, her children and her friends as they try to understand the tragedy and accept their personal loss, especially its unforeseen and unimaginable suddenness.
The Problem of Induction
If you missed it on Monday (January 26), L. Gordon Crovitz had an interesting article in The Wall Street Journal entitled Bad News Is Better Than No News. In our zeal to complete a project, we missed it when it was published, but now mention to the reader that it is worth their time.
We like it because it is consistent with much that we’ve written on these pages since the blog’s inception, and especially since last September. For example: no one knows what the mortgage thingies are worth, the banks can’t lend because they don’t know how unsound THEY are, and the government’s actions have exacerbated the problem by not providing any resolution to the uncertainty. Our solutions: nationalize the worst banks and provide generous tax incentives to buyers of the thingies to resolve the uncertainty.
Mr. Crovitz mentions: “Bankers now recall the fine print of VaR analysis, which is that it always includes low but real risk that some new element could make the historical data a poor measure of the future.”
This, of course, is the Problem of Induction, but unlike Mr. Crovitz, we don’t think that there is necessarily a low risk that past is not predictive of the future. (We could provide many citations to our old posts, but point new readers to our essay, Uncertainty Management, Or, Ignoramus et ignorabimus, Or How Trading is Like Playing in a Culvert on a Hot, Sunny, Summer Day. You can still drown from a flash flood on a sunny day. Actually, you could do it even without a flood.)
Feel free to search other posts for complaints about boards and senior managers, but here’s a brief recap of what we think happened: many experienced traders left the big banks for more lucrative options, and they were replaced during times of unusual placidity by junior traders without much of a historical perspective. Through lax control, e.g., greed combined with poorly-designed incentives, and because the folks who generate (short-term) revenue tend to win internal arguments with risk managers – if those arguments even occur – the organizations were over-confident and unprepared for adversity.
Moreover, the over-reliance on mathematical models, which were perfectly fine when nothing was happening, allowed the banks to avoid the consideration of tail-events. Those event are so unpleasant to comtemplate, anyway, so why bother?
To even hypothesize that really bad things could happen could be taken as a sign of weakness or incompetence by undisciplined managements, and probably were. (We think that is a silly perspective in the financial markets and in life in general, and it is one of the reasons that although we don’t hunt, we’re a huge proponent of second amendment rights. As we mentioned previous posts, we view guns as the equivalent of deep, out-of-the-money puts: they’re generally an inconvenience, but they do help manage tail risk.)
Back to our story: bad stuff starts to happen, and no one admits they’re wrong – prices will bounce back, right – or knows how to react (until everyone panics at the same time).
Mr. Crovitz quotes a late J.P. Morgan executive as saying that traders should earn their big money for managing the tail-risk, not the typical, daily volatility, but that advice seemed to have been ignored in hopes of profits and continued stability.
We think that another water analogy is appropriate. Placid times are like slow moving streams: it’s easy to wade out into the deep parts without too much concern. That’s despite the fact that algae thrives in such environments (and makes the bottom quite slippery). It doesn’t take much of a change in current – or even a misstep – to turn that confidence into panic. Moreover, it doesn’t even have to be your misstep when there are other folks nearby grasping at anything when they start to fall – especially ones who overestimated their own ability or the stream’s constancy and overstepped the bound.
Multi-period Bond Price Implied Default Rates and CDS
Implied Under the Assumption of Risk Neutrality
We have several posts related to the calculation of price-implied default rates under the assumption of risk neutrality and several posts related to simple CDS calculations.
Those posts have involved discrete, single-period problems, where there are only two dates of interest: today and a future date where an uncertain claim or cash flow will be realized, i.e., when bankruptcy would occur.
We’ve focused on binary models and will continue to do so here. In fact, to analyze a two-period problem, we’ll just build upon our latest post from December 2: Price Implied Default Rates.
We think that needless detail obfuscates the central points while providing no marginal explanatory power: either in a statistical or pedagogical sense. So, we like to keep things simple.
Note that we’re providing examples of simple, reduced-form models à la Jarrow and Turnbull (1995) or Hull and White (2000), not a structural Merton model like KMV. We’ll do that when we have the time.
In our December 2nd post, we considered a risky, one-year, zero-coupon bond. We assumed a face value of $1,000, a risk-free rate of 5%, and the risky bond’s yield to be 8%. We could have stated that last assumption as the bond has a price of $925.93.
From those assumptions, and the additional assumption that the owner of the bond would recover 60% of the face value, we calculated the risk-neutral-model-implied default rate of 6.94%.
Now the calculation of that default rate depends upon all of the assumptions, and obviously the answer will vary with changes in any of the assumed variables: the bond’s price or yield, the risk-free rate, and the loss given default rate.
Obviously, it also depends upon the applicability of risk-neutral valuation, which allows us to impose two very important considerations (versus reality). It allows us to (1) treat the bond’s price as the expected value of its cash flows, which is only valid if the creditor (in the model, not in real life) is risk-neutral, and (2) use the risk-free rate as the proper discount rate for a risk-neutral person. Those assumptions allow us to work with expected cash flows, rather than curvy preferences. We’ll focus on calculations in this post and not on applicability.
Finally, the answer also depends upon our choice of probability functions. Here, the only uncertainty involves full payment or not; so, that credit risk is easily modeled as a binary function, but it is important to note that risk-neutrality does not imply a particular probability function. Once the analyst has chosen from a family of distribution functions, the assumption of risk neutrality will determine (imply) particular parameter values, but that is all. For the more mathematically inclined, that is the change-of-measure that is referred to in the texts. (Probabilities are weights. Different parameter values within a distribution cause possible events to be weighed differently; ergo, the measure is changed.)
In this problem, we’ll keep the same assumptions as in our previous post for the first of our two periods. So, here is the setting: We have two zero-coupon, risky bonds issued by the same firm and each with a face value of $1,000: one matures in one-year and the other matures in two years. Imagine that there are two risk-free bonds, too.
The one-year risky bond is described as above; so, it will have a price of $925.93. If that bond were risk-free, it would have a price of $952.93. In a risk-neutral model, the difference in prices is the present value of the expected loss (of the risky bond, of course).
The risk-free rate in the second period is 7%. Note that there is no market risk – that is, no interest rate risk – so there is no evolution of interest rates or any type of rate process in our humble, little example. (We’re just making up numbers to illustrate a few basic ideas.)
The bond that matures in two years has a yield-to-maturity of 9.982%, which for all intents and purposes – and for everyone except the truly anal – is 10%.1
As an aside, with our two sets of interest rates, we can calculate an overall yield-to-maturity from our term structure of forward, risk-free rates, and for risky rates, we can determine the structure of forward rates from our risky yield curve.
Risk-free yield-to-maturity: we don’t really need to calculate this, so you can skip it is you want, but if the risk-free bonds are priced to earn 5% in the first year, and a two-year bond is priced to earn 7% in the second year, then the geometric average return for the zero-coupon, risk-free bond better be close to the arithmetic mean of 6%. That yield-to-maturity is simply:
[(1 + r1)·(1 + r2)]1⁄2 — 1 = [1.05·1.07]1⁄2 — 1 = 5.995%
So, the yield on a two-year, zero-coupon, riskless bond is about 6%: just like we knew before we did the calculation.
Risky forward rate: now, given the risky yield-to-maturity is about 10% on the two-year, zero coupon, bond, and given a first-year risky rate of 8%, then the implied forward rate for the second period must be:
[(1 + 0.08)·(1 + r2)]1⁄2 — 1 ≈ 10% implies r2 = 1.12 /1.08 - 1 = 12%
So, if (and only if) the two-year, risky bond yields (about) 10%, then its price is:
$1,000 ÷ 1.12 = $826.45 ≈ $826.72.
By the way, we’re off by 26¢ by using the easy 10% instead of the more precise 9.982%, but the lesson is free; so, the reader really shouldn’t complain.
Notice that credit spread increased from 3% (8% — 5%) in the first year to 5% (12% — 7%) in the second. All things equal, we should expect that the risk-neutral, price-implied, default rate will increase, too. Let’s see if that happens.
Three Probabilities of Default (or default rates): when we move to a multi-period problem, we have to be careful to specify the default rate to which we’re referring. There are conditional, marginal, and cumulative probabilities of default, and that is true whether we’re discussing actual (but unknown) probabilities of default or risk-neutral-implied probabilities of default like we’re doing here.
The conditional probability of default for a period, t, is the easiest notion to understand: given that the firm has survived until the beginning of that period, it is the probability that the firm can’t pay its bills during the next interval of time; here, we’re using one year as the time interval. We’ll denote conditional probabilities as pt for every period t.
The marginal probability of default is the probability that the firm will default in period t. Now, the firm only has the opportunity to default in period t, if it hasn’t already defaulted; so, the marginal probability considers the probability of surviving until that point and the conditional probability of default. If p1 is the (marginal) probability of default in the first period, the (1 — p1), then the marginal probability of default is:
(1 — p1)·p2,
For our little problem, we won’t introduce any special notation for the marginal probabilities of default.
Finally, the cumulative probability of default is the sum of all the marginals: p1 + (1 — p1)·p2 in a two-period problem. We wrote about longer term cumulative probabilities of events in this post, Good Column, Bad Math, where we talk about 100-year floods.
So, let’s find the conditional probability of default in the second period. Given that there was no default at the end of the first period, what is the probability of default in the second period implied by the bond’s price?
Well, with one period remaining, the price of the only remaining bond is:
$1,000 ÷ 1.12 = $892.86.
So, we can find the conditional probability of default in the second-period, p2, the same way that we found the probability in our one-period problem.2
price = $892.86= (1 — p2) × ($1,000 ÷ (1 + 0.07)) + p2 × (600 ÷ (1 + 0.07))
$892.86= (1 — p2) × $934.58 + p2 × 560.75.
So, if the firm survives the first period, there is an 11.16% conditional probability of default in the second period. That means that the marginal probability of default for the second period is the probability that the firm survives the first period multiplied by the conditional probability of default in the second:
(1 — p1) ·p2 = (1 — 0.0694) · 0.1116 = 10.385%
The cumulative probability of default is the sum of the two marginals: 6.94% + 10.39 = 17.33%.
Note that at the end of the first period the difference between the risk-free bond’s price of $934.58 and the risky bond’s price of $892.86 is $41.72. The $41.72 represents the risk-neutral, “present value” at the start of the second period of the conditional expected loss in the second period of the two-period bond. So, the $41.72 is related to the conditional probability of loss and the potential loss of $400:
($400 × 11.16%) ÷ 1.07.
But the second period will be experienced only if there was no default in the first period! So, in a risk-neutral world, a creditor will only experience the opportunity to lose (a discounted average) of $41.72 if there is no default in the first period: with probability (1 — 6.944%).
And the value of that today – at the start of it all – must be discounted by the first period’s risk-free rate of 5%. So, the present value of that expected loss that
$41.72 × (1 — 0.06944) ÷ 1.05 = $36.97.
Is our analysis correct? Let’s see. A two-year, risk-free, zero-coupon bond would have a price of $890.08. Our risky bond has a price of $826.45. That means that in a risk-neutral world – given all of our assumptions – the present value of the sum of the expected losses is the difference: $890.08 — $826.45 = $63.63.
In the first year, the present value of the expected loss on debt with a face value of $1,000 is $26.67. That means that the present value of the expected loss in the second period must be: $63.63 — $26.67 ≈ $36.97. Hey, where did we see that number before? That’s right — a few inches above where we discounted the expected present value of the second-period loss.
What about CDS?
To protect against loss, the CDS should provide $400 in case of default at the end of each period.
If the CDS policy were sold period-by-period, i.e., one-year terms, the first year’s premium would have to be at least $26.67 and the second year’s if sold today would cost at least $36.97. The actual cost, like everything else in the real world, would depend upon how badly creditors want to protect against loss, but those values are actuarially fair in a risk-neutral setting.
Also note that if the CDS policy were sold at the start of the second period, the premium would have be to at least $41.72 to be actuarially fair in a risk-neutral world. So, if purchased consecutively, the insurance premiums would need to $26.67 today and $41.72 next year in our risk-neutral world.
What if the insurance were purchased for two periods? What would the constant premium be? In that case, there is a chance that one or both premiums will be received (or paid). If there is no bankruptcy in the first period, then the premium will be paid twice; so, we need:
premium + (1 — 0.06944) premium ÷ 1.05 = $63.63
premium (1.0 +0.93056 ÷ 1.05) = $63.63
premium = $33.74
We assumed that the premium was paid at the beginning of each period; so, it is like an “annuity due” and actually is like a random, annuity due. It’s random because it is a constant stream of cash flows, but the ending date is unknown. In this simple two-period example, the “stream” could be one or two payments.
Also remember that risk-averse creditors should be willing to pay more than that, i.e., a risk premium, too.
And remember, we’ve said absolutely nothing about probabilities in the real world that our example represents. Risk neutral probabilities and default rates are derived from a set of assumptions that permits (relatively) easy calculation, but those probabilities and rates only work in our model, and they do not represent real frequencies. For more on that, please see our other posts on the topic.
As we hope that you can see, CDS is identical to term life insurance – except millions and millions of similar firms don’t die each year; so, there is little empirical evidence of various factors, including loss given default rates.
By the way, we’ve ignored counter-party risk and a host of other complicating assumptions.
As with many of our longer posts, we’ll likely edit this one in the near future.
Copyright © 2008 Spero Consulting.
Footnotes:
- By the way, can you imagine the number of folks who would scream that 9.982% isn’t 10%; so, they would indict us for not being precise thus we are wrong, wrong, wrong. That might be despite the fact that they may have been involved in allowing their organizations to accumulate billions of dollars of losses all the while arguing for precision. We do love those ironies of life. Also, the fact that we’ve made life simple by not continuously compounding would upset a few, too. ↩
- Just to be clear, we could have found the “future value” of the price by multiplying $892.86 by 1.07 and using the face value of $1,000 and the recovery (upon default) value of $600. In other words, we could have solved: $955.35714= (1 — p2) × $1,000 + p2 × $600. ↩
Price Implied Default Rates
Update: December 12, 2008. While none of our analysis or calculations was incorrect, we did have a minor error in the penultimate paragraph. We should of said “first” not “last.” To make amends, here is a multi-period problem, Multi-period Bond Price Implied Default Rates and CDS, but it won’t make sense without reading this one first. We also added a few paragraphs below, which should help explain the multi-period case.
Further update: April 14, 2008. We also have a new, related post on default rates. It is Calculating Counterparty Credit Reserves from April 8, 2009. Much of that post involves default rates, too.
We see that we’re getting a number of hits from search engines for folks looking for information about price-implied default rates – possibly college students with homework assignments or people trying to understand the various types of default rates they may encounter in their jobs or readings.
We have a number of posts on risk-neutral default rates, including Implied Risk Neutral Probabilities (of Default) , implied RISK NEUTRAL probability of default, redux, Risk Neutral Valuation: There Are at Least Two Expected Values, but we doubt if those settings are the ones that all guests want to see, especially those looking for help on their homework. (Of course, we think they are all worth reading.) So, as a public service, we offer an example of a simple, one-period bond problem. (It is single-period because it is gratis, after all.)
Suppose that a zero-coupon, risky bond with a face value of $1,000 matures in exactly one year. (Yeah, we said it was simple.) We’ll ignore compounding issues and assume that the annual risk-free rate is 5%. We’ll also assume that this risky bond’s yield-to-maturity is 8%.
Let’s calculate and discuss a few things before we provide additional assumptions.
We’ll calculate the bond’s price that corresponds to an 8% yield, and we’ll calculate the bond’s price if it were riskless; of course, by riskless we mean free of default risk or credit risk, only. Our simple one-period model doesn’t really permit interest rate risk, which is a type of market risk.
The bond’s price with a 8% annual yield is: $1,000 ÷ (1 + 0.08) = $925.93.
Now, if the bond were risk-free, its price would be $1,000 ÷ (1 + 0.05) = $952.38,
which is $26.45 higher. So, the price drops and the yield increases (over their risk-free equivalents) because the owner(s) of the bond is forced to bear some type of credit risk or probability of loss.
That $26.45 will appear again later, but at this point we can’t say much more than it is the difference in the prices of a one-period risk-free bond and our one-period risky bond.
The problem with simple calculations – whether in one or multiple periods – is that they ignore all of the factors that actually affect and determine prices. In other words, we’ve completely ignored the market dynamics and factors that would cause the price to be $925.93.
The market-clearing price would depend upon supply and demand considerations.1 Those considerations would depend upon the preferences, beliefs, and endowments of actual and potential sellers and buyers. In our simple setting, the important preferences would be risk and time preferences, which could possibly be expressed as utility functions; beliefs would involve the probability of default as well as other probabilities associated with each agent’s wealth in other assets if they exist – i.e., their endowments.
So, we can think of the price of $925.93 as a “function” of preferences, U(·); beliefs, f(·); and endowments, w.2 Unfortunately, in real life, we don’t know those factors; so, we’ll never be able to solve the actual problem, but we can solve a substitute problem.
All we know is that the price is $925.93, and it can be expressed as a yield-to-maturity – or a yield curve for multi-period problems – of (our assumed) 8%. So, the yield could be viewed as a function of the price if you want, but they’re really determined simultaneously.
As we’ve written many times before in related posts, because of several clever researchers in economics and finance, we can actually do more than just discuss the tautologies of price and yield.
In certain cases, we can assume that market participants are risk-neutral – that takes care of U(·) and makes the w irrelevant – and we can assume a particular form of a density or distribution function of outcomes, f(·). Very importantly, with those assumptions, if we don’t know one of the parameters of f(·) we can solve for it if we know everything else. That would be like solving for the misnamed implied vol or implied default rate, which is what we will do here.3
Here’s the key to all risk-neutral pricing: under certain assumptions, if agents are (assumed to be) risk-neutral, then we can treat prices as equal to the expected value of the asset’s cash flows according to an associated density function. That’s the only time we can treat prices as expected cash flows, rather than expected utilities, but depending upon the level of the course, some profs are pretty bad at explaining that fact.4
So, there are three things to consider. First, if agents are risk neutral, we can assume that they care only about expected values.
Second, if agents are risk neutral, then they won’t pay a premium for taking risk like risk-lovers would, nor will they need to be paid a premium for taking risk like risk-averse agents would need to be paid.
Third, that means we can assume that risk neutral agents are satisfied earning the risk-free rate. 5 So, given all of our words above, that means that risk neutral agents would value assets at the discounted value of the expected cash flows – discounted at the risk-free rate.
So, as we showed above, if the bond were actually risk-free, then price would have been $952.38, but the price is $925.93. That means that market participants must expect to receive less than the face value of $1,000 at least some percentage of the time, and that percentage is the probability of default.
Let’s see exactly how much less than $1,000, but first note that we could write the price of a risk-free bond in a slightly expanded way. Risk-free means 100% chance of getting $1,000; so,
Equation A:
$952.38 = 100% × ($1,000 ÷ (1 + 0.05)) + 0% × (value given default ÷ (1 + 0.05))
We did nothing but add zero to our previous calculation of a risk-free bond.
Let’s make it risky. Let p represent the probability of default, then for a risk-neutral person, we could write that same line as:
price = (1 — p) × ($1,000 ÷ (1 + 0.05)) + p × (value given default ÷ (1 + 0.05))
Thus, with a price of $925.93, we could write:
$925.93 = (1 — p) × ($1,000 ÷ (1 + 0.05)) + p × (value given default ÷ (1 + 0.05))
There are two unknowns: the probability of default, p, and the value of the bond given default, which has to be less than $1,000. In fact, we could put a determine a upper bound that is less than $1,000 if we wanted to do so. (How?)
Now, look at the last equation. Once we know or assume the value given default, we could find the probability of default, p, or vice versa.
Usually, one assumes the value given default and solves for p. There’s not really a good reason for doing it other than that’s what just about everyone does. (Don’t let anyone attempt to fool you with some lame justification. It’s tradition, custom, convention. Regardless of the word, it is arbitrary.)
So, let’s make-up – er, we mean assume – a value given default. This is often given in terms of a loss given default, a loss given default rate, or a recovery rate, but they’re all equivalent as one can see in the following relationships.
value given default = $1,000 — loss given default
value given default = $1,000 — loss given default rate × $1,000 = $1,000 × (1 — loss given default rate)
value given default = $1,000 × (1 — loss given default rate) = $1,000 × recovery rate
The loss given default is often abbreviated LGD. Unfortunately, the loss given default rate is sometimes abbreviated as LGD. Don’t let the bad notation fool you. Now, where were we?
That’s right. Let’s suppose that the loss given default rate is 40%. That means the recovery rate is 60%, which is its complement. Regardless, of how that assumption is stated, that means that the value given default is $600. So, now we have another number to put into our equation:
$925.93 = (1 — p) × ($1,000 ÷ (1 + 0.05)) + p × (600 ÷ (1 + 0.05))
or,
Equation B:
$925.93 = (1 — p) × $952.38 + p × 571.43.
If we did the arithmetic correctly, then solving for p gives a probability of default of almost 7%: 6.94%. Clearly, all things equal, which means holding everything else constant, as the loss given default increases, the probability of default decreases. One can make a graph of that relationship as we did in Implied Default Probabilities and Risk Neutral Models in June, 2008.
Now, under the assumption of risk-neutral agents, the difference between the two bond prices of $26.45 can be express as the difference in the present value of their expected cash flows. The difference in the present values of the expected cash flows in Equations A and B is the present value of the expected loss. The loss given default is $400. The undiscounted expected loss is: 0.0694 × $400 = $27.76. The present value of the expected loss is – not surprisingly – $27.76 ÷ 1.05 = $26.45.
That’s not the most someone would spend for insurance. That insurance premium depends upon the person’s risk-aversion.
Multi-period problems aren’t that much different, but they require bonds of multiple maturities if one is attempting to derive a credit curve, and one works for from the last first period forward solving maturity-by-maturity. Otherwise, one can find an “average” annual marginal probability of default. (We talk about a similar issue in Good Column, Bad Math.) So, in our multi-period example, we’ll explain the price of a two-year bond as the difference in present values between a risky and risk-free two-year bond. Then we’ll say much much of that can be attributed to the first period and then the second period.
Note: WE“VE SAID ABSOLUTELY NOTHING ABOUT THE REAL PROBABILITY OF DEFAULT! If all of the agents are risk-averse, then the unknown real probability of default will be less than the risk-neutral rate, but that’s not too helpful, is it? Some of our older posts do illustrate this idea.
Good luck with the assignment.
Copyright ©2008 Spero Consulting.
Footnotes:
- That’s quite a vacuous statement. ↩
- We are purposely using U(·) for preferences to remind readers of utility functions; f(·) for beliefs to remind individuals of probability density functions; and w for endowments to remind of their other wealth. Also, we put the quote around function, because we’re definitely not using it in its strict mathematical sense. ↩
- The implied is misnamed; it is inferred. It’s implied by the model selected, but it is inferred or imputed by the analyst. ↩
- Risk neutrality is actually slightly more general than that. ↩
- That’s why the actual yield is greater than the risk-free rate because market participants tend to be risk averse, but we don’t know the exact form of that aversion. ↩
Volatility and Losses: No End in Sight
If you haven’t read it, For the Vix, 40 Looks Like It’s the New 20 in today’s The Wall Street Journal please know that is a decent column.
We particularly like the paragraph:
“Volatility may not return to its highs, but it isn’t clear when it will get back to normal, either. Volatility breeds fear, which breeds more volatility. There is still too much uncertainty about the losses lurking on bank balance sheets and about the depth and breadth of the current recession to inspire much calm.”
Now, the first sentence is true but says absolutely nothing. We’re not trying to ridicule Mark Gongloff the writer of the Ahead of the Tape column; instead, we empathize with the difficulty he faces writing about markets and uncertainty.
The notion of uncertainty about uncertainty–and the inability to measure it in a simple manner – tends to make statements about the topic either sound overly-complex and overly-qualified (by all of the necessary descriptive qualifications to the statement) or makes them sound trite. Sometimes that’s the writer’s fault, but often it is the reader’s fault, too, especially when the reader incorrectly possess no uncertainty about their own “knowledge.”)
Now, we especially like Mr. Gongloff’s following sentences because that’s almost exactly what we’ve written during the past several months – almost three months now.
The mortgage crisis that created the confidence and liquidity crisis and the resulting equity market volatility all continued unabated. Last Wednesday, in The Mortgage Crisis: Why Not Incentivize the Private Sector? we wrote: “By the way, folks who think this Thanksgiving week’s mini-rally signifies that the worst is over are likely to be sadly mistaken. We do hope that we’re wrong, but doubt it.”
While we try not to make much of one-day changes, even when they are as large as today’s drop of 680 points in the DJIA and the nearly 9% decreases in the S&P 500 and NASDAQ indices, we do believe both the continuing volatility and losses provide evidence that the government’s actions to date have not helped instill confidence. In all likelihood have hindered economy and financial activities by not allowing any resolution of the uncertainty of the value and viability of large financial intermediaries.
We wrote about that in Could a “Bailout” Prolong the Financial Crisis? and The Uncertain Value of Mortgage Securities (among other posts) in late September. However, the government’s execution and lack of planning has been even worse than we could have imagined, and we had extremely low expectations to begin with.
As we have been mentioning since that time, we wish federal government would provide tax incentives – say, mortgage investment tax credits – to motivate private purchases of troubled assets.
We also wish the government would expropriate the worst offenders – the most poorly capitalized large banks. We know that the Treasury can’t run banks any better than the existing managements, but that’s not one of our reasons. A main reason is to motivate other healthier institutions to act. Having ready buyers – motivated by such tax credits – would certainly help those banks exchange assets for cash, and that lack of trade keeps the analyses of each bank’s financial conditional needlessly opaque, and that’s (by definition) no way to resolve uncertainty.
We’re not sure when during the day, Mr. Paulson spoke of new programs (Paulson Says Treasury Actively Mulling New Rescue Programs), but we doubt if that stemmed the (ebbing) tide of sharply decreasing equity values. Unfortunately, there is no reason to expect any positive news any time soon.
The Seventy-Year-Old Teenager
The Curious Case of Robert Rubin
The weekend edition of The Wall Street Journal has a front page interview with Robert Rubin: Rubin, Under Fire, Defends His Role at Citi.
We’ve criticized Citi’s board in the (recent) past, and we’re still particularly fixated on the fact that few directors had financial industry experience. That seems neither wise nor even prudent for a financial institution with over $3,000,000,000,000 of assets. (That’s $3 trillion, but we like to write it out for effect, because it seems like a lot of money.)
As the article mentions, Mr. Rubin was “the only board member with experience as a trader or risk manager.”
Since 1999, Mr. Rubin has made about $119 million from Citigroup while having no operating responsibilities. We have absolutely no problem with that, and, in fact, are looking for similar “work” ourselves. (Interested parties may use our contact form.)
Where we do have a problem is his insistence that none of Citi’s problems is his responsibility. As the inside headline reads: “Rubin Blames Citigroup’s Woes on the Broader Financial Crisis.” He almost seems to imply that Citigroup is a hapless, unwitting victim of something bigger than itself – something it couldn’t be expected to consider, manage, of fathom: “Nobody was prepared for this…”
In that case, exactly what type of stewardship, guidance, and profundities did he provide?
Suppose it is true that Citi and its board were faultless. Shouldn’t they have been able to consider how they might be damaged by a general downturn or a financial crisis that was no fault of its (their) own. Thus, our little proof-by-contradiction shows the silliness of the argument.
Moreover, we doubt that even the gullible buys the story that Citi was simple a victim of exogenous factors, which were unpredictable and beyond its control.
There is a crisis of confidence, but that crisis erupted and survives because markets and investors realized the large financial institutions, including Citigroup, were far less competent investing and trading than they previously believed, i.e., that in retrospect, previous reported profits were unreal and unsustainable.
Citigroup’s share price of $8.29, which is about double where it was last weekend, has lost about 85% of its value in two years. (In the first three years of the Great Depression – 1929 — 1932 – the Dow Jones Industrial Average lost the same percentage without a backstop by government.) That is an indictment against Citigroup’s way of doing business far beyond the general condemnation of the financial services industry in general and with all of the subsidies provided by tax payers through the various recent government guarantees and bailout measures.
Clearly, investors find fault with Citi’s strategic and operating decisions. So, if Mr. Rubin wasn’t making operating decisions, what type was he making? If they weren’t strategic, what remains? As other critics note, Mr. Rubin is “trying to have it both ways.”
Of course, his posturing is silly, as it was he, himself, who pushed senior management to bear more risk in 2004 — 2005. If that’s not a strategic, board-level, decision, what is? From our reading, it seems that he may now be trying to blame a consultant for suggesting the board instruct managers to take additional risk.
He also blames senior management for not executing the strategic plans properly and risk management for, well, weak risk management.
“I wouldn’t run a financial institution based upon someone’s view about what markets would do.”
Of course, as the article explains that is exactly what he did in 2004 — 2005. (We wouldn’t doubt that he did it at other times, too, but don’t have the time or energy to search for quotes or stories.) Well, he didn’t do it based upon someone else’s view; instead, Citi’s strategy seemed to be based upon his own views. (We could well imagine boardroom discussions where inexperienced directors immediately defer to the former Treasury Secretary and Goldman Sachs Co-Chair.
Now, Mr. Rubin should know that developing and acknowledging such a world-view is exactly how financial institutions are run, whether that view is explicitly stated or not. (If it is not explicit, then not providing such a view and or considering its implications seems negligent at worst and immature at best, ergo, our title.) What else could strategic and operating plans be based upon? How else could risks be measured, uncertainties be considered, and contingencies be planned? Or are those considerations too much like work? If so, it is not difficult to see why Citi is where it is at this November, and that is completely consistent with both a specific and the more general crisis in confidence.
As we see it, Mr. Rubin is seventy-years-old. He should grow-up and accept the responsibilities that come with his position and rewards, and stop behaving like a petulant teenager.
Gossamery Arguments for Transparency and Our Reply
Recently, we’ve seen many op-ed essays calling for more transparency in financial statements, particularly with respect to mortgage-related securities. Many of these essays have been written by famous and esteemed individuals or their staffs.
In our own idiosyncratic, round-about way, we’ll explain the empty silliness of such arguments, and we begin by criticizing the notion that “more is always better.”
Too Much Information: Unfortunately, we’ve not read a single essay that contained an intelligent, concrete argument for why more transparency is better than less – as if transparency, in and of itself, is a good (or is inherently good).
More precisely, in all of these articles, the value of transparency is assumed, and the assumption seems to be implicit and subconscious (unconscious?) rather than something arrived at via serious deliberation. (Hint: we can’t recall any of these essays that bother to define transparency. Presumably, it is like pornography: you know it when you see it.)
In that half-assed way, these recent prompts for more transparency have much in common with the slightly older admonitions to eliminate mark-to-market accounting.1
In their theories, many economists – including, yours truly – have shown that more transparency, which often means more precise information, is not always better than less; in fact, it can make things strictly worse. Such seemingly pathological results are actually rather common in a variety of social settings, including some markets, and arise for a number of reasons, including risk-sharing and incentives, where more information can affect an agent’s behavior and actions or efforts thereby reducing social welfare and/or exacerbating incentive problems.
For example (and this is a gross generalization of the results without specifying any of the necessary assumptions) in Kanodia, Singh and Spero (JAR, 2005), we show that it is better to keep two unknown variables as unknowns rather than know only one with perfect precision. Think of it in the following way: suppose there are two random variables – one that is somewhat in the person’s control and the other, which is not.
If the one under his influence is known perfectly, he’ll overemphasize it. If the other one is known perfectly, then he’ll rightfully conclude that the noisy signal of his effort will be overlooked in favor of the other variable so he’ll do little. The former creates over-exertion and the latter creates under-exertion and both are socially damaging; thus, one can find a happy medium in less extreme cases where neither variable is known with total precision. (It should remind one of Goldilocks.)
Now, let’s be very clear that one need not be an economist to know that more information or transparency is not always better. For example, how does the reader answer questions from a spouse, relative, or friend when asked something like, “Do you like my new haircut?” or “Does this dress make me look fat?”
In addition, there are other cases where another party reveals personal details with too much precision. In fact, we as a society have the colloquialism, “Too much information!” for just such cases where you’ll never again look at the revealer in the same manner and subsequently ruefully wonder, “why did they have to tell me that?”
Details Are Not Information: this is a particularly apt time to repeat our admonition that details are not information. Back in April, we posted a long essay on the difference between details and information or useful facts. (Useful facts are ones that might cause a decision to change as the fact is realized.) Our point in that essay was to distinguish between keeping track of a lot of necessary data – as in data processing – and the quite different task of providing useful information to decision-makers. If one leaves systems design to systems people, one will likely get the former and not much of the latter. Moreover, if the decision-maker can’t design the system – not the programming – then his or her competence at decision-making should be justifiably questioned.
The same distinction between details and information holds true with financial assets, too. More transparency can mean an inundation of book-keeping and account details, which may provide no information or which may require expert judgment to (sift through to) become information. In either case, the recipient of the data dump may not “see the forest for the trees.“2 So, one may have all the facts, but no ability to organize them – much like a child writing a term paper.
And, that, of course, illustrates the silliness of calling for more transparency for mortgage-related securities. The bigger problem is that with every datum about every mortgage in a pool, there is still no easy way to value them.
The issue isn’t the details, it is how to combine current and past details to determine value and risk in the future, and it is very likely a perfect method is unknowable. So…
Value Matters, BUT There’s No Transparent Way to Find It: let’s illustrate the notion in to a fairly high level of detail (for a blog post). We’ll ignore the “waterfall” aspect of real mortgage-backed securities and CDOs where different classes of security holders have different priority claims on the cash flows because those claims are not the confounding factors – the interelationships of the mortgages are.
So, imagine a pool of T thousand mortgages going down the first column of a spreadsheet. Further, suppose that the next 360 columns represent months, m, so, the row t and column m intersection is the amount of cash received from borrower t in month m. Now that cell will actually be a function of any number of factors, including interest rates which affect whether the mortgage is repaid early; the person’s wealth and income which determine whether the borrower declares bankruptcy, the relationship between the value of the collateral and the loan balance, etc. We could go on and on, but the point is that each cell could take any number of values depending upon many different factors.
One page of the spreadsheet would then represent one entire scenario of how cash is received from all T thousand mortgages over the next thirty years.
At issue for valuation (and risk modeling) is how to combine outcomes across all mortgages. The cells are clearly related within a row, i.e., a borrower’s status in one month will affect cash flows in later months.
But, cash flows are also related within columns – phenomena, like a hurricane, may contemporaneously affect more than one borrower – and across columns, too. For example, someone’s default in month m may make another’s default in month m + n more likely. So, the bigger issue is: how does one relate borrowers across time and space to arrive at a distribution of cash flows. (Note: we mean “space” literally because community and regional effects matter – the inter-row action, sometimes.)
One could generate any number of scenarios or pages, but, of course, the issue for valuation (and risk) are which combinations in the numerous T x 360 grid are more (or less) likely (and how wide is the range of possible outcomes)?
In other words, the problem lays with determining the joint distributions across borrowers and time. As we see it, there is no correct method, but there is an infinity of incorrect methods, especially ones that rely only on historical relationships, particularly very short histories.
Those incorrect methods include many that were implemented in recent years. As we see it, many of those methods were implemented because they were solvable, not because they were accurate. Unfortunately, those weaknesses (inaccuracies) were obscured by the relative calmness of the markets, including the near-Ponzi-like schemes of different banks buying the securities to re-securitize them yet another time.
So, we ask those writers urging more transparency: exactly how would it help us find a price in the above example? Our illustration highlights the reason why there is a lack of buyers. There are data aplenty. What is lacking is a quantifiable notion of the future.
That, dear reader, is why we developed and wrote about an alternative solution to TARP. One that involved the use of investment tax credits or cash-basis accounting (to permit the immediate expense of the purchase price) to subsidize and cushion the risk of purchasing these conglomerations of cash flows. It would provide private buyers with an immediate benefit of 30% — 40% of the purchase price, which seems large enough to permit room for error.
As always, we encourage visitors to read our essay, Uncertainty Management, which discusses the notions of measurability (quantifiability) and immeasurability by distinguishing between the broader idea of uncertainty and the narrower idea of risk. In that regard, the number and cost of mis-specification errors related to our ongoing crisis may be the greatest in any period in history.
We’ll probably edit this again in the near future.
Footnotes:
- As we mentioned on Halloween, sometime around October 1, we saw a Congressman from Tennessee rant about mark-to-market accounting. It’s quite possible that he had a deep understanding of the topic, but if that were the case, then he was about articulate as a frenzied ninth-grader sending text messages during the middle of a soda-and-cake-induced sugar-high. While that’s possible, it is also highly unlikely. Our inference was that the man had no idea of the topic of his conversation. While we listened to his diatribe against mark-to-market accounting, we thought, hmmm, not a single specific reference to the underlying issues of relevancy, reliability, economic efficiency, etc. Not even in layman’s terms. Replace “mark-to-market accounting” in his otherwise generic spiel, “we have to something about mark-to-market accounting before it…,” and he had a ready-made speech for all that is evil du jour: AIDs in Africa, the lack of clean water in villages, illegal drugs, legal drug manufacturers, drunk driving, international piracy, child labor, greed, foreign car manufacturers, cancer, diabetes, Wall Street executives, oil prices, etc., and no other words would have changed. He had a handy demonization template, and that made actual contemplation superfluous. A the time, we thought, that it is quite unfortunate there is no required literacy (or aptitude) tests to vote in Congress. ↩
- This actually is very much an epistemological issue. For example, consider the four elements of the ancient Greeks – water, earth, wind, and fire. Even in the bronze age, there was substantial evidence that earth, at least, could be sub-divided into more basis elements. Although those new elements were used technologically, they were not to become part of any science or perspective until much later. ↩
The Understatement of the Year!
Behind AIG’s Fall, Risk Models Failed to Pass Real-World Test.
You Don’t Say! Our subtitle is the title of today’s Wall Street Journal front-page article about AIG (obviously).
As always we’ll point interested readers to our essay, Uncertainty Management, which emphasizes the broader notion of unmeasurable uncertainty over the narrower notion of (measurable) risk, and therefore permits really bad things to happen.
We mean bad things outside the scope of someone’s purely mathematical model, which, as an abstraction of reality, may ignore imaginable and unimaginable bad things. (We’re all for math – when it is thoughtfully and conscientiously applied. In fact, we think such application is one of the things that we do best.)
In that regard, we’ll once again note the subtitle of the above-referenced essay, Or How Trading is Like Playing in a Culvert on a Hot, Sunny, Summer Day. See dear reader, once one considers that one could drown from a flash flood – even on a presumably and locally Sunny day – the allure of such adventure dulls greatly – at least for the reasonable among us.
In other words, your mother may have been a scold, but there was probably a good reason for her to warn you about playing in culverts and drainage ditches (provided that she loved you, of course). She may not have discussed it in probabilistic terms, but that doesn’t mean she can’t recall reading about such drownings, say, forty years ago, or even before you were born.
Moreover, the fact that you didn’t read about any such cases in, say, the past ten years, doesn’t mean they don’t exist, and there, of course, lies the Problem of Induction, and the over-reliance on inferences from relatively short-duration, historical, data sets. (See our beautiful excerpt from St. James’ only Epistle on our Quotes page.)
The problem, dear reader, is that few senior managers (and almost no board members) understand the valuation and risk models used for securitizations, and many of the traders, consultants, and analysts who wield such tools often suffer from, what one may call, “framing” issues; we don’t mean that aspect of home construction despite its recent relevance.
We mean that if one’s only tool is a hammer, then lots of things look like nails. The metaphoric hammer may be an intangible Visual Basic or “C” programming algorithm, but the point remains the same; it’s just harder for senior management to see what one is pounding in their cubicle, office, or trading-floor seat.
To be sure, if anyone within most of the larger firms would have complained of the systematic risk – and how everything could go bad all at once – and the inapplicability of the standard models, which generally don’t permit such events, then that person most certainly would have been told that they don’t know what they’re talking about. Possibly, that they are unsophisticated or too negative.
Perhaps we just don’t pay enough attention to what happens in all of the large firms, but if the reader disagrees with our preceding paragraph, please note that there have been few recent success stories within major firms like the gains enjoyed by Nassim Nicholas Taleb, John Paulson, or Andrew Lahde–all independent fund managers. (If the new reader has read this far, then it is highly likely that they’ll like the link under Andrew Lahde’s name and his condemnation of many things in one fell swoop.) We know that our examples form a very small data set, but mostly what we’ve heard is how the more successful large firms haven’t lost as much as their brethren. We don’t recall any of them actually do well this year.
Also, we’ll probably have more to say about our boy, Taleb. We very much like his trading style, as it reminds us of the value of the Second Amendment and laws that permit concealed carry. See, dear reader, carrying a pistol is very much like buying deep-out-of-the-money puts. There’s a small, ongoing cost and a minor irritation, but when certain bad things happen, there is an option to exercise to protect ones self, and that value cannot be underestimated.
We haven’t said anything about CDS – the source of AIG’s problems – in this post but plan to do so shortly.
The Role for Survivalists and Depressives in Uncertainty Management
We think that the current turmoil in the markets provides an atmosphere for independent thinkers and adviser such as ourselves to gain some attention (and more clients) by commenting on current issues and by offering free and useful advice, especially if said advice is difficult to implement without us. For that reason, we’re in the middle of writing a few longer posts about a variety of topics related to the ongoing financial crisis.
One of those unfinished posts, “Hedging the Pennywise and Pound-Foolish Way,” deals with myopia and tunnel-vision, and it is the impetus for this post.
Here, we contemplate a few types of personalities that would be beneficial hires for financial firms, but readily admit that it is highly unlikely that most firms could or would ever knowingly employ such folks. Their corporate cultures, particularly their emphasis on hope and conformity, eliminate such individuals from employment consideration. So much for diversity we guess!
Among the group of personalities that we have in mind are the survivalist and the depressive.
First, as regular (and by this time, possibly even occasional) readers may know, we prefer “uncertainty management” to “risk management,” because that is the true nature of the task. One needs protection from unknown and/or immeasurable bad things, too. The task is about loss prevention not just the narrower ex ante measurable loss prevention.
Above we highlighted our broader emphasis on uncertainty, rather than merely risk, because such consideration of extremely bad events tends to be the nature of both survivalists and depressives.
Between the two groups – we’ll ignore the depressed survivalist intersection for a few paragraphs – it seems that survivalists spend more time developing strategies and tactics to cope with the bad outcomes than they do fixating on their causes (although we’re sure that many have their favorite conspiracy theories, too).
Conversely, depressives seem to spend much more time contemplating all of the bad things that could happen and all the ways that those events could arise; many have sufficient imaginations to construct the necessary chain of events to arrive at, say, Armageddon – both literally and figuratively. In fact, that’s what tends to make them so depressing to be around, and it is also what makes them unlikely to pass a day-long sequence of interviews at an investment commercial bank.)
Unfortunately, they often spend so much time wallowing in the despair of such losses that they don’t possess the necessary coping skills or the determination/drive to provide useful solutions. That, of course, is what survivalists specialize in: being prepared for the worst.
Now, we conjecture that few survivalists would view most money center locations as the optimal high ground on which to camp when Western Civilization falls, especially if said money center were, say, a small island of several million people with extremely-limited, natural, non-cannibalistic food sources and very restrictive gun control to boot.
Of the cognoscenti, we’d view one of our favorites, Nassim Nicholas Taleb, the author of Fooled By Randomness, as the person whose trading strategies most closely embrace the the intersection of the survivalist/depressive mentality in markets. (He seems to have too much fun justly annoying fools to be either depressed or overly-fixated on survival.)
Based upon his reported trading success, it would seem that at least on a small scale, analogs to our recommendation can be profitable. As we understand it, Mr. Taleb would often buy deep-out-of-the-money puts figuring that in the long run, he would gain outsized returns because (1) others would under-estimate the probability of bad outcomes, and (2) he had an exact strategy and tactics in place to benefit from such occurrences. Ergo, the successful, depressive-survivalist trade.
However, as Mr. Taleb repeatedly mentions, such beliefs (and the strategies and actions that they induce) require a substantial degree of discipline to implement. Successful bets are few and far between, and it takes much stamina, patience, and determination to wait on the occasional win. Moreover, it is psychologically painful when friends, neighbors, and former colleagues are making immediate money on seemingly senseless and random trades and you’re wait for that extreme event.) We’d imagine that the level of frustration felt and the discipline required to cope with it, aren’t much different than what’s needed to seat next to a survivalist or depressive on the trading floor.
Finally, we’d be remiss not to mention our other favorite author in the field, Richard Bookstaber, author of A Demon of Our Own Design. In that excellent book, he admonishes traders and risk managers to keep their strategies simple and robust. He points to the cockroach as an exemplary evolutionary survivor with a very simple physiological structure.
We disagree with him slightly, because our tiny insectoid brain is not concerned with the entire survival of the species– but only with our own personal viability. So, Mr. Bookstaber’s long-run is likely quite a bit longer than we (and most others) care about. However, he does describe the problems and costs of complexity; thus, the title of the book. We wholeheartedly agree with him on those issues, e.g., no one understands the whole system; such things tend to be jerry-rigged à la Rube Goldberg; and the (initial) failure of a safety system can destroy the entire entity, etc. Some of those things are very scary when they happen in airplanes and nuclear plants.
In that regard, our recommendations to hire for personality might not seem that outrageous: it is simple and robust. Perhaps a few knowledgeable and imaginative depressives and survivalists are worth an army of lemming-like quants attempting to “over-calculate” the unknowable?
Look for our upcoming book series: Essential Risk Management I: Embrace Your Inner Survivalist and Essential Risk Management II: Embrace Your Inner Depressive. No, not really.
