Economics

The Soulful Science?

Posted by Peter on December 15, 2008
Posted in: Economics, Idea Futures. Tagged: .

Book review: The Soulful Science: What Economists Really Do and Why It Matters by Diane Coyle.
This book provides a nice overview of economic theory, with an emphasis on how it has been changing recently. The style is eloquent, but the author is too nerdy to appeal to as wide an audience as she hopes. How many critics of economics will put up with quips such as “my Hamiltonian is bigger than yours!”?

The most thought-provoking part of the book, where she argues that economics has a soul, convinced me she convinced me she’s rather confused about why economics makes people uncomfortable.
One of her few good analogies mentions the similarities between critics of evolution and critics of economics. I wished she had learned more about the motives of her critics from this. Both sciences disturb people because their soulless autistic features destroy cherished illusions.
Evolutionary theory tells us that the world is crueler than we want it to be, and weakens beliefs about humans having something special and immaterial that makes us noble.
Likewise, economics tells us that people aren’t as altruistic as we want them to be, and encourages a mechanistic view of people that interferes with attempts to see mystical virtues in humans.

Some of her defenses of mainstream economics from “post-autistic” criticism deals with archaic uses of the word autistic (abnormal subjectivity, acceptance of fantasy). These disputes seem to be a disorganized mix of good and bad criticisms of mainstream economics that don’t suggest any wholesale rejection of mainstream economics. It’s the uses of autistic that resemble modern medical uses of the term that generate important debates.

She repeats the misleading claim that Malthusian gloom caused Carlyle to call economics the dismal science. This suggests she hasn’t studied critics of economics as well as she thinks. Carlyle’s real reason (defending racism from an assault by economists) shows the benefits of economists’ autistic tendencies. Economists’ mechanistic models and lack of empathy for slaveowners foster a worldview in which having different rules for slaves seemed unnatural (even to economists who viewed slaves as subhuman).

I just happened to run across this thought from an economist describing his autistic child: “his utter inability to comprehend why Jackie Robinson wasn’t welcomed by every major league team”.

She tries to address specific complaints about what economists teach without seeing a broad enough picture to see when those are just symptoms of a broader pattern of discomfort. Hardly anyone criticizes physics courses that teach Newtonian mechanics for their less-accurate-than-Einstein simplifications. When people criticize economics for simplifications in ways that resemble creationists’ complaints about simplifications made in teaching evolution, it seems unwise (and autistic) to avoid modeling deeper reasons that would explain the broad pattern of complaints.
She points to all the effort that economists devote to analyzing empirical data as evidence that economists are in touch with the real world. I’ll bet that analyzing people as numbers confirms critics’ suspicions about how cold and mechanistic economists are.

She seems overconfident about the influence economists have had on monetary and antitrust policies. Anyone familiar with public choice economics would look harder for signs that the agencies in question aren’t following economists’ advice as carefully as they want economists to think.

I’m puzzled by this claim:

The straightforward policy implication [of happiness research] is that to increase national well-being, more people need to have more sex. This doesn’t sound like a reasonable economic policy prescription

She provides no explanation of why we shouldn’t conclude that sex should replace some other leisure activities. It’s not obvious that there are policies which would accomplish this goal, but it sure looks like economists aren’t paying as much attention to this issue as they ought to.

She appears wrong when she claims that it’s reasonable to assume prediction market traders are risk neutral, and that that is sufficient to make prediction market prices reflect probabilities. Anyone interested in this should instead follow her reference to Manski’s discussion and see the response by Justin Wolfers and Eric Zitzewitz.

Chinese Stock Risks

Posted by Peter on December 11, 2008
Posted in: China, Investing.

There are lots of small Chinese companies trading on U.S. stock exchanges that look at first glance to be ridiculously underpriced. One reason for the low prices are that it’s harder than you might expect to enforce U.S. law on Chinese companies that have few or no assets in the U.S.

The most blatant example I’ve seen is Eternal Technologies Group Inc, which has ignored a judgment in a lawsuit that seems minor compared to the cash the company reports having, with the result that a receiver has been appointed who is likely to collect some money in ways that badly hurt stockholders who bought before the lawsuit.
Another hint at how little the company cares about stockholders (at least those in the U.S.) is the careless way their press releases are written: “5. Radification of the elecrion of the auditors” (they managed to spell election correctly on the prior line, so it’s not simple ignorance).

I’ve noticed problems with other U.S. traded Chinese companies that leave me uncertain which of them can be trusted. I’ve been trading stocks listed on the Hong Kong Stock Exchange a fair amount, and haven’t noticed any similar problems there. I presume the stronger cultural and/or legal ties are more effective than anything that can be accomplished by U.S. law.

Intrade versus FiveThirtyEight

Posted by Peter on November 6, 2008
Posted in: Idea Futures, U.S. Politics. Tagged: , .

A number of people have compared the final forecasts for the election (e.g. this), but I’m more interested in longer term forecasting, so I’m comparing the state-by-state predictions of Intrade and FiveThirtyEight on the dates for which I saved FiveThirtyEight data a month or more before the election.

Here is a table of states where Intrade disagreed with FiveThirtyEight on one of the first four dates for which I saved FiveThirtyEight data or where they were both wrong on July 24. The numbers are probability of a Democrat winning the state’s electoral votes, with the Intrade forecast first and the FiveThirtyEight forecast second.

State 2008-07-24 2008-08-22 2008-09-14 2008-10-01
CO 71/68 60/53 54.5/46 67.5/84
FL 42/29 34.5/28 30/14 55.2/70
IN 38/26 34.1/15 20/11 38/51
MO 50/26 32.9/13 22.1/11 42.5/48
NC 30/22 25/21 14/7 51/50
NV 51.2/49 49/45 44.9/32 55/66
OH 65/53 50/38 40/29 53.5/68
VA 60.5/50 52.3/36 42/22 59/79

On July 24, both sites predicted Florida, Indiana, and North Carolina wrong. FiveThirtyEight got Indiana right on Oct 1 when Intrade was still wrong, but Intrade got North Carolina right on that date (just barely) while FiveThirtyEight rated it a toss-up.
Intrade got Nevada right on July 24 (just barely) while FiveThirtyEight got it wrong (just barely).
For Virginia, Intrade was right in July and August while FiveThirtyEight was undecided and then wrong.
FiveThirtyEight got Colorado wrong on September 14, but Intrade didn’t.
FiveThirtyEight got Ohio wrong on August 22, while Intrade got it right.
Intrade rated Missouri a toss-up on July 24, while FiveThirtyEight got it right.

On September 14, FiveThirtyEight was fooled by McCain’s post convention bounce by a larger margin than Intrade, but by Oct 1 FiveThirtyEight was more confident about correcting those errors.
For states that were not closely contested, there were numerous examples where Intrade prices where closer to 50 than FiveThirtyEight. It’s likely that this represents long-shot bias on Intrade.

In sum, Intrade made slightly better forecasts for the closely contested states through at least mid September, but after that FiveThirtyEight was at least as good and more decisive. Except for Intrade’s Missouri forecast on July 24, the errors seem largely due to underestimating the effects of economic problems – errors which were also widespread in most forecasts for other things affected by the recession.

In the senate races, I didn’t save FiveThirtyEight forecasts from before November 1. It looks like both Intrade and FiveThirtyEight made similar errors on the Alaska and Minnesota races.
[Update on 2009-01-13: contrary to initial reports, they apparently got the Alaska and Minnesota races right, although there’s still some doubt about Minnesota.]

On the other hand, Intrade had been fairly consistently (but not confidently) saying since early July that California’s Proposition 8 (banning same-sex marriage) would be defeated. Pollsters as a group did a somewhat better job there by issuing conflicting reports.

Automated Market Maker Changes

Posted by Peter on November 1, 2008
Posted in: Idea Futures. Tagged: , .

I’ve made a change to the software which should fix the bug uncovered last weekend.
I’ve restored about half of the liquidity I was providing before last weekend. I believe I can continue to provide the current level of liquidity for at least a few more months unless prices change more than I currently anticipate. I may readjust the amount of liquidity provided in a month or two to increase the chances that I can continue to provide a moderate amount of liquidity until all contracts expire without adding more money to the account.
I’m not making new software public now. I anticipate doing so before the end of November.

Stock Market Crashes

Posted by Peter on November 1, 2008
Posted in: Investing. Tagged: .

Many people seem to be reacting to the recent stock market crash the way they wish they had to the 1987 crash, and a smaller number are comparing it to 1929.
The unusual resemblance to the crash of 1937 makes me expect something in between those two scenarios.

  • The 1937 crash was caused in part by a sudden increase in caution by banks after the Fed significantly increased their reserve requirement. Banks played no interesting role in the 1929 or 1987 crashes.
  • The 1929 and 1987 crashes followed stock market peaks in August, versus March and the prior October for the 1937 and 2008 crashes.
  • The 1937 and 2008 crashes both came eight years after one of history’s largest stock market bubbles.
  • The 1929 and 1987 crashes followed an increase in the discount rate to 6 percent. The 1937 and 2008 crashes followed decreases in the discount rate to 1 and 2.25 percent.

All four crashes happened mainly in October and their behavior in that month provides little reason for distinguishing them.
If the 1937 crash is a good model for what to expect in our near future, many investors who are currently following the lesson they learned from the 1987 crash will discover in early 2009 that the unexpectedly severe recession casts doubt on the belief that crashes create good buying opportunities. How many of them will stick to their buy and hold commitment then (when I expect it will be a good idea)?
When the extent of the recession becomes disturbing, remember Brad DeLong’s perspective:

Is 2008 Our 1929? No. It is not. The most important reason it is not is that Bernanke and Paulson are both focused like laser beams on not making the same mistakes as were made in 1929….
They want to make their own, original, mistakes..

(HT James Hamilton).

Automated Market Maker Problems

Posted by Peter on October 26, 2008
Posted in: Idea Futures. Tagged: .

Last night an Intrade trader found and exploited a bug in my Automated Market Maker, manipulating DEM.PRES-TROOPS.IRAQ until Intrade rejected one of the market maker’s orders for lack of credit and the software shut down.
The bug involves handling of partial executions of orders, and doesn’t appear to be easily fixable (what happened looks nearly identical to the scenarios I had analyzed and thought I had guarded against).
For the moment, I’ve reduced the market maker’s order size to one contract, which will prevent further exploitation but provide much less liquidity.
I will try to fix the bug sometime in November and increase the order size (on the contracts that don’t get expired at election time) by as much as I can without adding more money to the market maker’s account. I will also analyze the information provided by the markets shortly after the election.

Misbehavior of Markets

Posted by Peter on October 5, 2008
Posted in: Book Reviews, Investing.

Book review: The Misbehavior of Markets: A Fractal View of Risk, Ruin & Reward by Benoit Mandelbrot.
Mandelbrot describes some problems with financial models that are designed to provide approximations of things that can’t be perfectly modeled. He pretends that pointing out the dangers of relying too much on imperfect approximations shows some brilliant insight. But mostly he’s just translating ideas that are understood by many experts into language that can be understood by laymen who are unlikely to get much value out of studying those ideas.
His list of “ten heresies” is arrogantly misnamed. Sure, there are some prestigious people whose overconfidence in financial models leads them to beliefs that are different from his “heresies”, but those “heresies” are closer to orthodoxies than they are to heresies.
His denial of the equity premium puzzle is fairly heretical, but his argument there is fairly cryptic, and relies on suspicious and poorly specified claims about risk.
He says market timing works, but the strategy he vaguely hints at requires faster reaction times than are likely to be achieved by the kind of investor this book seems aimed at.
His use of fractals doesn’t have any apparent value.
Mandelbrot is primarily a mathematician with limited interest in understanding how markets work. One clear example is his mention of a time when Magellan “was still a small fund, too small for any detractors to argue that its size alone gave it a competitive edge”. Any informed person should know that’s completely backward – larger funds have a clear disadvantage because they are limited to trading the most liquid investments.
Another example of a careless mistake is when he claims the evidence suggests basketball players have hot streaks, seemingly unaware that Tversky and others have largely debunked that idea.

Wall Street vs Intrade

Posted by Peter on September 29, 2008
Posted in: Idea Futures, Investing.

The stock market reacted to today’s defeat of the bank bailout bill with an unusually big decline. Yet the news wasn’t much of a surprise to people watching Intrade, whose contract BAILOUT.APPROVE.SEP08 was trading around 20% all morning. Why did the stock market act as if it was a big surprise?
Did Intrade traders make a lucky guess not based on adequate evidence? Did they have evidence that the stock market ignored? Could the stock market have priced in an 80% chance of the bill being defeated (if so, that would seem to imply that passage would have caused the biggest one-day rise in history)? Could the stock market have been reacting to other news which just happened to coincide with the House vote? (It looks like the market had a short-lived jump coinciding with news that House leaders hoped to twist enough arms to reverse the vote, but I wasn’t able to watch the timing carefully because I was at the dentist).

It seems like one of these must be true, but each once seems improbable.

Arnold Kling, whose comments on the bailout have been better than most, was surprised that the bill failed.

I covered a few of my S&P 500 futures short positions at near the end of trading, but I’m still positioned quite cautiously (I made a small profit today).

Moral Hazard with Credit Default Swaps

Posted by Peter on September 17, 2008
Posted in: Investing.

Charlie Munger in the August 31, 2008 issue of Outstanding Investor Digest:

Let’s say you’re insuring against the outcome that people will lose money on a $100 million bond issue, and the credit default swaps, instead of amounting to $100 million, amount to $3 billion. Now you’ve got people with $3 billion worth of contracts that really have a big incentive in having somebody fail. And they may manipulate in some fraudulent or extreme way to cause a default in order to make the big collection.

There doesn’t seem to be enough transparency in financial systems to figure out whether this concern is relevant to this week’s panic.