Bayesian Investor Blog

Book review: Greatness: Who Makes History and Why by Dean Keith Simonton.

This broad and mediocre survey of psychology of people who stand out in history probably contains a fair number of good ideas, but it’s hard to separate them from the many ideas that are questionable guesses. He’s inconsistent about distinguishing his guesses from claims backed by good evidence.

One of the clearest examples is his assertion that childhood adversity builds character. He presents evidence that eminent figures were unusually likely to have had a parent die early, and describes this as the “most impressive proof” of his claim. He ignores the possibility those people come from families with a pattern of taking sufficiently unusual risks to explain that evidence.

In other places, he makes mistakes which seemed reasonable when the book was published, such as “Mendelian laws of inheritance are blind to whether an individual is first-born or later-born” (parental age has a measurable effect on mutation rates).

He avoids some of the worst mistakes that a psychology of history could make, such as trying to psychoanalyze individuals without having enough information about them.

He mentions some approaches to analyzing presidential addresses and corporate letters to stockholders, which have some potential to be used in predicting whether leaders have the appropriate personality for their jobs. I wonder what would happen if many voters/stockholders demanded that leaders pass tests of this nature (I’m assuming the tests can be scored objectively, but that may be shaky assumption). I’m confident that we’d get leaders with rhetoric that passes those tests. Would that simply mean the leaders change their rhetoric, or would it be hard enough to maintain a mismatch between rhetoric and thought patterns that we’d get leaders with better thought patterns?

Book review: Why He Didn’t Call You Back: 1,000 Guys Reveal What They Really Thought About You After Your Date by Rachel Greenwald.
This book is designed for women who want to debug their dates with men, and some of the book is specific to that goal. But a majority of the book is gender independent, and a fair amount of it describes how misunderstandings can arise in a wide range of interactions between people who don’t know each other well.
The book isn’t very profound, but it is based on fairly careful research that ought to be done more often than it has been. I was surprised at how much I enjoyed reading it and how quickly I finished it.
I’m not convinced I learned a lot from it. The problems that appear to best describe my interactions with people are the ones that I find relatively hard to change.
I suspect she overestimates her ability to get accurate reasons from the men, but I don’t have much reason to think the men who are misleading her are men who her clients could have better connected with.

The amount of time people spend sitting is positively correlated with mortality. The obvious alternatives to sitting causing bad health appear to be inadequate to explain the correlation.

Book review: Historical Dynamics: Why States Rise and Fall by Peter Turchin.

Turchin uses the tools and perspective of population biology to model some important aspects of the growth and collapse of empires. The relatively dry and mathematical style of the book makes it slow reading, but it leaves less ambiguity than most books about history. He has no obvious political biases - it often seems that his main bias is a preference for the tools of biologists over the tools of historians.

One important aspect of his approach is that it models the dynamics of a feature that is roughly described by terms such as solidarity, trust, and cooperation. He convinced me that he has described some of the influences that cause that feature to increase and decrease (the section title “Frontiers as incubators of group solidarity” says a good deal about his model).

Some aspects of the book left me wondering whether his eccentric worldview added anything to my understanding of history, but occasionally he comes up with ideas that have implications that are clearly new to me, such as his suggestion that monogamy can help an empire continue it’s expansion for a longer time.

He makes some serious attempts to test his models against the available data. It’s hard to tell whether enough data is available to adequately test such ambitious claims.

The biggest limitation of the book is that he assumes Malthusian conditions. While it is likely that some of his analysis applies to the industrial world, he thinks it’s premature to ask how much of it applies today. That means it ought to be of interest mainly to historians for now.

Book review: The Invisible Hook: The Hidden Economics of Pirates by Peter Leeson.

This is an interesting history of early eighteenth century pirates with an economist’s insights into what influenced them to have institutions such as democracy and to be in many ways pleasanter to serve on than commercial or military ships of the same time.

He has a fairly open bias toward portraying pirates favorably. I sometimes wondered whether there’s enough evidence to support his sometimes surprising conclusions. He makes plausible claims to be getting his historical information from the relevant experts, but without careful checking I can’t tell whether he has slanted his story to make it more entertaining.

He describes some good reasons why “workers’ democracy” doesn’t work as well in modern corporations as it did on pirate ships. But he is too willing to accept the observed absence of corporate democracy as evidence of its inefficiency. I can easily imagine that managers grab more power than is good for the company, and that principal-agent problems let them get away with it (pirates’ relations with the law made it easier for them to remedy this via mutiny). Also, he overstates the claim that “workers don’t have the finances required” for worker ownership of corporations. There are plenty of companies with low enough capital requirements for this to be unimportant. The big difference I see between modern corporations and pirate ships is that pirates had strong reasons to stick together until their venture got enough loot for them to all retire at once and divide the results. Employees in modern corporations want much more flexibility in when they leave the company, which creates complications for workers’ democracy or for the employee who wants to leave however it is handled.

One analysis whose absence disappointed me was whether the long-term benefits to joining a pirate ship were better than those of commercial or military ships. What fraction of pirates retired wealthy? How many of them were fooled by a temporary shortage of law enforcement into adopting a career with an abnormally high death rate once governments increased law enforcement?

He occasionally digresses into standard economics rants that have no relevance to pirates, such as the two pages on lobbyist rent-seeking.

Book review: Good and Real: Demystifying Paradoxes from Physics to Ethics by Gary Drescher.

This book tries to derive ought from is. The more important steps explain why we should choose the one-box answer to Newcomb’s problem, then argue that the same reasoning should provide better support for Hofstadter’s idea of superrationality than has previously been demonstrated, and that superrationality can be generalized to provide morality. He comes close to the right approach to these problems, and I agree with the conclusions he reaches, but I don’t find his reasoning convincing.

He uses a concept which he calls a subjunctive relation, which is intermediate between a causal relation and a correlation, to explain why a choice that seems to happen after its goal has been achieved can be rational. That is the part of his argument that I find unconvincing. The subjunctive relation behaves a lot like a causal relation, and I can’t figure out why it should be treated as more than a correlation unless it’s equivalent to a causal relation.

I say that the one-box choice in Newcomb’s problem causes money to be placed in the box, and that superrationality and morality should be followed for similar reasons involving counterintuitive types of causality. It looks like Drescher is reluctant to accept this type of causality because he doesn’t think clearly enough about the concept of choice. It often appears that he is using something like a folk-psychology notion of choice that appears incompatible with the assumptions of Newcomb’s problem. I expect that with a sufficiently sophisticated concept of choice, Newcomb’s problem and similar situations cease to seem paradoxical. That concept should reflect a counterintuitive difference between the time at which a choice is made and the time at which it is introspectively observed as being irrevocable. When describing Kavka’s toxin problem, he talks more clearly about the concept of choice, and almost finds a better answer than subjunctive relations, but backs off without adequate analysis.

The book also has a long section explaining why the Everett interpretation of quantum mechanics is better than the Copenhagen interpretation. The beginning and end of this section are good, but there’s a rather dense section in the middle that takes much effort to follow without adding much.

Book review: Evidence-Based Technical Analysis: Applying the Scientific Method and Statistical Inference to Trading Signals, by David Aronson.

This is by far the best book I’ve seen that is written for professional stock market traders. That says more about the wishful thinking that went into other books that attempt to analyze trading rules than it does about this author’s brilliance. There are probably books about general data mining that would provide more rigorous descriptions of the relevant ideas, but they would require more effort to find the ideas that matter most to traders.

There hasn’t been much demand for rigorous analysis of trading systems because people who understand how hard it is to do it well typically pick a different career, leaving the field populated with people who overestimate their ability to develop trading systems. That means many traders won’t like the message this book sends because it doesn’t come close to fitting their preconceptions about how to make money. It is mostly devoted to explaining how to avoid popular and tempting mistakes.

Although the book only talks specifically about technical analysis, the ideas in it can be applied with little change to a wide variety of financial and political forecasting problems.

He is occasionally careless. For example: “All other things being equal, a TA rule that is successful 52 percent of the time is less valuable than one that works 70 percent of the time.” There might be a way of interpreting this that is true, but it’s easy for people to mistake this for a useful metric, when it has little correlation with good returns on investment. It’s quite common for a system’s returns to be dominated by a few large gains or losses rather than the frequency of success.

The book manages to spell Occam three different ways!

Book review: Hollywood Economics: How extreme uncertainty shapes the film industry, by Arthur De Vany.

This rather dense and scholarly book that contains some good insights into how markets for information differ from markets for physical goods. But few people will want to read the whole book. Much of the book was originally published as papers in economics journals. It’s better organized than that suggests, but the style is mostly oriented toward professional economists.

Much of the book can be summed up by the conclusion that nobody knows anything about how successful a movie will be. The typical film loses money, and the expected returns are heavily dominated by rare films that are huge successes.

He says through much of the book that returns on investment in movies have infinite variance, and only at the very end admits that that’s not literaly true, and then provides a more credible description of the variance as unstable and generally increasing over time.

His argument that Hollywood makes too many R-rated films takes a good deal of effort to follow. Table 5.3 is confusing, because it shows a mean return on R-rated films as much higher for the returns on PG13 films. This sounds like the opposite of his conclusion. It took 13 more pages before I figured out that that was due to some high rates of return on low budget R-rated films that had little effect on aggregate profits. It appears that his conclusion ought to have been that Hollywood makes too many high-budget R-rated films, and too few low-budget R-rated films.

His description of the antitrust cases that transformed the movie industry provides convincing evidence that the courts were confused and didn’t help the independent exhibitors that the lawsuits were allegedly designed to help. The arguments about how they affected consumers are less clear.

At last Sunday’s Overcoming Bias meetup, we tried paranoid debating. We formed groups of mostly 4 people (5 for the first round or two) and competed to produce the most accurate guess to trivia questions with numeric answers, with one person secretly designated to be rewarded for convincing the team to produce the least accurate answer.

It was fun and may have taught us a little about becoming more rational. But in order to be valuable, it should be developed further to become a means of testing rationality. As practiced, it tested some combination of trivia knowledge and rationality. The last round reduced the importance of trivia knowledge by rewarding good confidence intervals instead of a single good answer. I expect there are ways of using confidence intervals that remove the effects of trivia knowledge from the scores.

I’m puzzled about why people preferred the spokesman version to the initial version where the median number was the team’s answer. Designating a spokesman publicly as a non-deceiver provides information about who the deceiver is. In one case, we determined who the deceiver was by two of us telling the spokesman that we were sufficiently ignorant about the subject relative to him that he should decide based only on his knowledge. That gave our team a big advantage that had little relation to our rationality. I expect the median approach can be extended to confidence intervals by taking the median of the lows and the median of the highs, but I’m not fully confident that there are no problems with that.

The use of semi-randomly selected groups meant that scores were weak signals. If we want to evaluate individual rationality, we’d need rather time consuming trials of many permutations of the groups. Paranoid debating is more suited to comparing groups (e.g. a group of people credentialed as the best students from a rationality dojo, or the people most responsible for decisions in a hedge fund).

See more comments at Less Wrong.

This paper reports that people with autistic spectrum symptoms are less biased by framing effects. Unfortunately, the researchers suggest that the increased rationality is connected to an inability to incorporate emotional cues into some decision making processes, so the rationality comes at a cost in social skills.

Some analysis of how these results fit in with the theory that autism is the opposite end of a spectrum from schizophrenia can be found here:

It seems that the schizophrenic is working on the basis of an internal model and is ignoring external feedback: thus his reliance on previous response.I propose that an opposite pattern would be observed in Autistics with Autistics showing no or less mutual information, as they have poor self-models; but greater cross-mutual information , as they would base their decisions more on external stimuli or feedback.