Saturday, May 30, 2015

A Test for Truth

I have been reading an interesting account of how conscription was ended in the U.S., focusing on my father's role. Near the end of the process, President Nixon established a commission headed by Thomas Gates, a former secretary of defense. Martin Anderson recounts the following exchange between Nixon and Gates: 
But Mr. President, I’m opposed to the whole idea of a volunteer force. You don’t want me as the chairmen.”
“Yes, I do Tom,” the president replied, “that’s exactly why I want you as the chairman. You have experience and integrity. If you change your mind and think we should end the draft, then I’ll know it’s a good idea.”
It struck me as an ingenious solution to the problem faced by someone who needs to make decisions on a variety of questions and does not have the time and energy to research all of them for himself. Instead of trying to appoint a neutral agent to give an unbiased opinion, appoint someone whose honesty and competence you trust who is on what you suspect is probably the wrong side of the question. If you are right, about both him and the question, he will change his mind. If he does not, you may well be wrong.

Assuming that Nixon's explanation of his choice is true, the incident is to his credit.

The commission, set up with people on both sides of the issue, ended by unanimously recommending the abolition of the draft.

Sunday, May 17, 2015

Torture and Revealed Preference

One of the latest episodes in the war against ISIS was a raid by U.S forces that killed a leading figure and captured his wife. According to news stories, the intent was to capture Abu Sayyaf, believed to play a major role in financing ISIS via black market sales of oil, for the sake of  valuable information he could provide about ISIS operations. Killing him, while better than nothing, was not the preferred outcome.

That raises an obvious question. Assuming the raiders had been successful, how did they expect to get at information in Abu Sayyaf's head? The most obvious conjecture is by torture—which the U.S. government claims not to engage in. An alternative possibility is by threatening his wife—also not, so far as I know, a tactic U.S. forces admit to using. 

A central principle of economics is revealed preference. What people do provides more reliable information than what they say.

Politicians as People

Politicians are also people, and the question of what sort of people they are is largely separate from the question of what policies they advocate. That struck me recently after I happened to interact casually with two professional politicians, both at a fairly high level. One of them was, loosely speaking, on my side. One was, loosely speaking, on the other side.

The politician I agreed with was a nice enough person, but did not feel like someone it would be fun to spend time arguing with. The reverse was true of the politician I disagreed with. The reason was not that I can't argue with people on my side—I can and frequently do. It was something about the feel of their personalities.

By that standard, my favorite modern politician would probably be Newt Gingrich. I've never met him, but at one point I somehow got on a mailing list for cassette tapes of his talks—by the technology you can guess how long ago it must have been. Pretty obviously, he was bright, opinionated, original, a little crazy. The sort of person I enjoy arguing with.  The overall feel reminded me a little of my friend and ex-colleague the late Gordon Tullock. I am pretty sure that if, by some accident, Gingrich and I were seated next to each other on a long plane flight, neither of us would be bored.

Tuesday, May 12, 2015

Liberals and Elizabeth Warren

My previous post mentioned the controversy over Elizabeth Warren's claim to be a native American. The facts, as best I can determine them, are that she put herself on the minority law teacher list in her listing in the faculty directory of the American Association of Law Schools, from the mid-eighties until after she received tenure at Harvard, represented herself as native American to both the University of Pennsylvania and Harvard, and was so listed in federal filings by both universities. 

When questioned, Warren explained that she believed, from family tradition, that an ancestor had been Cherokee. When the issue arose during her 2012 senatorial campaign, supporters claimed to have documentary evidence that one of her great-great-great grandmothers had been listed as Cherokee. It eventually turned out that the claim was based on an assertion in a 2006 family newsletter—no actual documentation ever appeared. For an account from a source friendly to Warren, see this Mother Jones article. For a much more detailed account from a critical source, this web page.

Most of the controversy has been over whether Warren's claim was true, but that does not strike me as the interesting question. I not only have no documentary evidence with regard to any of my great-great-great grandmothers or even my great grandmothers, I don't even know their names. And, in any case, what is relevant in evaluating Warren's behavior is not what is true but what she believed.

I will assume, therefor, that Warren really did believe that she had a distant ancestor who was Cherokee. We are still left with the case of a woman who took advantage of preferential hiring policies designed to benefit disadvantaged minorities by claiming to be one in spite of not being a member of a disadvantaged minority in any meaningful sense. 

That is not admirable behavior, but neither is it, in my view, strikingly wicked—people quite often game systems for their own advantage in one way or another. But then, I am not a supporter of affirmative action. One would expect those who are to see it as a modern version of the proverbial offense of stealing pennies from a blind man's cup, diverting to her benefit resources that were supposed to go to other and worse off people. Yet Elizabeth Warren has not only not been ostracized by the liberal community, she has become one of their leading figures.

I can only see two plausible explanations. The less likely one is that most liberals do not really believe in their own proclaimed principles, do not care whether affirmative action policies actually benefit the people they are supposed to benefit. The more likely one is that this is an example of tribal behavior. Warren won back a blue tribe senate seat from a red tribe usurper. That gives her a free pass, the social equivalent of a get out of jail free card. Any evidence against her, however clear, is obviously enemy propaganda to be ignored.

Monday, May 11, 2015

The Trust Problem

In a recent Facebook exchange about Elizabeth Warren's claim to be a native American, someone raised the issue of what news sources one should rely on, comparing Breitbart unfavorably to Mother Jones. In support of that comparison, she cited a web page, NewsTrust, which posts its evaluations of news sources and gives Mother Jones a high rating.

That raises an obvious question that apparently had not occurred to her: What reason do we have to trust NewsTrust? To answer that I looked at their web page and discovered that the single source of information for which it showed the highest rating was Rolling Stone, the magazine responsible for the bogus UVA rape story—not merely a mistake, but a mistake pretty clearly due to irresponsible reporting with an ideological bias. Add to that the fact that the two blogs which they rate on that page are Daily Kos and Think Progress, both well to the left, and I conjecture that their ratings tell me more about which side a source is on than about how reliable it is.

That leaves us with the problem of how to figure out what facts to believe, given that not only news sources but sources of information about news sources are likely to be biased in various ways. In that particular exchange, I had already demonstrated one solution to that problem. The Mother Jones article was introduced to the discussion by me, as evidence against Warren, not for her. Both the politics of the publication and the tone of the story made it clear that any bias would be in Warren's favor. Hence I concluded that any negative evidence it presented was probably true—and cited that evidence in the exchange.

For a detailed discussion of the controversy over the evidence on Warren's ancestry, see this Breitbart piece and its links. Believe it or not as you wish.

Saturday, May 09, 2015

Why Good Teachers Get Bad Evaluations

The current Slate Star Codex, my favorite blog, has a link to an account of an interesting piece of research on student evaluations of teachers. It judged the quality of teachers by how well their students did in later courses,  compared the result to student evaluations of teaching quality, and found that the two anti-correlated. On average, good teachers get bad ratings, bad teachers get good ratings. For details, follow the link.

It's a single study, I have not read the original paper, and the result might be wrong. But it is interesting to think about reasons why it might well be right.

The most obvious one is that many students don't like to work hard. A professor who does not assign much homework or reading and grades easily might get better ratings, from many although not all students, than one with the opposite pattern. My daughter, as a student at Oberlin, was struck by the fact that most of the other students in a class were happy when, for some reason, it didn't meet. The same pattern—study seen as a cost, not a benefit—might well apply here.

There is a second and less obvious possible reason. Correct ideas are frequently hard. Easy ideas are frequently wrong. My standard example is from popular discussions of foreign trade issues. Most of them take for granted a view of the economics of trade, the view implicit in terms such as "unfavorable balance of trade," that  economists refer to as the theory of absolute advantage. That particular view of the subject has been obsolete for about two hundred years. But while the theory of absolute advantage does not make sense if you think about it carefully, it is considerably easier to understand than the theory of comparative advantage, which does. That is why the former was worked out first and why it has had such a successful postmortem career.

A professor who insists on telling the truth, on explaining hard ideas correctly, may well come across as a worse teacher than one who fudges, offers a simplified and less correct version. Half the students of the former end up believing that they do not entirely understand the subject being taught—and they are right. Almost all the students of the latter end up sure they understand it—and wrong.