Science and Society

Everyone’s talking about this Paul Krugman essay on where economics, as a discipline, went wrong. Partly, “going wrong” means the failure to appreciate the risks in our financial system, and the corresponding failure to predict the crash we’re currently trying to deal with. But from an insider’s perspective, something else has happened: an uneasy consensus between two different approaches to economics has been shattered. One, which Krugman labels the “saltwater” approach, is associated (in the U.S.) with some variety of post-Keynesian analysis, generally identified with some willingness to have the government intervene in the economy over and above the Fed’s control of the money supply. The other, the “freshwater” approach favored by the Chicago School and other inland economists, is more purely free-market and non-interventionist. (Truth in advertising: I am not an economist.) These camps could more or less get along when everything was going fine, but have dramatically different reactions to a crisis. To the extent that you find freshwater economists claiming that unemployment is currently high, not because there aren’t many jobs, but because there are too many incentives for people not to work.

One of the reasons it’s a great essay is that it’s a wonderful example of popularizing science. You can debate all you like about whether economics counts as a science, but there’s little doubt that Krugman does an amazing job at explaining esoteric ideas in non-technical language, and is so smooth about it that you hardly realize difficult ideas are even being discussed. I wish I could write like that.

One part of the essay worth commenting on, or at least musing about, is the punchline. Krugman thinks that a major factor leading to the failures of economics to understand the mess we’re currently in was the temptation to think that beautiful models must be right.

As I see it, the economics profession went astray because economists, as a group, mistook beauty, clad in impressive-looking mathematics, for truth. Until the Great Depression, most economists clung to a vision of capitalism as a perfect or nearly perfect system. That vision wasn’t sustainable in the face of mass unemployment, but as memories of the Depression faded, economists fell back in love with the old, idealized vision of an economy in which rational individuals interact in perfect markets, this time gussied up with fancy equations. The renewed romance with the idealized market was, to be sure, partly a response to shifting political winds, partly a response to financial incentives. But while sabbaticals at the Hoover Institution and job opportunities on Wall Street are nothing to sneeze at, the central cause of the profession’s failure was the desire for an all-encompassing, intellectually elegant approach that also gave economists a chance to show off their mathematical prowess.

Without knowing much of anything about the relevant issues, I nevertheless suspect that this moral might be a bit too pat. Sure, people can fall in love with beautiful theories, to the extent that they overestimate their relationship to reality. But it seems likely to me that the correct way of understanding all this, once it’s properly understood, will look pretty beautiful as well. General relativity is widely held up as an example of a beautiful theory — and it is, when understood in its own language. But if you put the prediction of GR in the Solar System into the language of pre-existing Newtonian physics (which you could certainly do), it would look ugly and ad hoc. Likewise, Newton’s theory itself is quite elegant, when phrased in the language of potentials on a fixed spacetime background; but if you express the theory in terms of differential geometry (which you could certainly do), it looks like a mess. Sometimes the beauty/ugly distinction between theoretical conceptions is more a matter of how well we understand them, and less about their intrinsic qualities.

So my counter-hypothesis would be that it wasn’t beauty that was the problem, it was complacency. If you have a model that is beautiful and works well enough, you’re tempted to take pride in it rather than pushing it to extremes and looking for problems. I suspect that there is a very beautiful theory of economics out there waiting to be developed, one that understands perfectly well that individuals aren’t rational and markets aren’t perfect. One that has even more impressive-looking equations than the current favored models! Beauty isn’t always a cop-out.

White Americans, anyway. That seems to be the result from this poll at Daily Kos (via Tom Levenson’s Twitter feed).

Research 2000 for Daily Kos. 7/27-30. Likely voters. MoE 2% (No trend lines)

Do you believe that America and Africa were once part of the same continent?

         Yes    No  Not Sure

All       42    26    32

Dem       51    16    33
Rep       24    47    29
Ind       44    23    33

Northeast 50    18    32
South     32    37    31
Midwest   46    22    32
West      43    24    33

White     35    30    35
Black     63    13    24
Latino    55    19    26
Other     56    19    25

Probably readers of this blog are not a representative sample of Americans, and most or you — even the white people! — know that Pangaea was the supercontinent that existed about 250 million years ago, before plate tectonics worked its magic and broke it apart.

Now, some of my best friends are white folks, so I don’t want to make any grand generalizations about their intelligence or education. But this is a good illustration of a point made by Jerry Coyne — the problem of scientific illiteracy is not a simple one, and in particular it’s not just a matter of better outreach and more Carl Sagans. Which is not to say that more and better outreach and science journalism isn’t important or useful — it clearly is, and I’m in favor of making structural changes to provide much better incentives for making sure that it happens. But there are also factors at work for which outreach isn’t the answer — political and social forces that push people away from science. Those have to be confronted if we want to really address the problem.

(I don’t know who was the mischievous person who thought of asking this poll question in the first place, but it was an inspired idea.)

Update: Aaron Golas in comments points to a post by Devilstower laying out that the question was worded in an intentionally provocative way, to illustrate how bad questions can fail to correctly gauge scientific understanding. Which is completely true, and a point worth making. But I argue that the poll does reveal something, namely the extent to which underlying cultural attitudes can influence one’s stance toward purportedly scientific questions. Thus, “White People Have Trouble Accepting Pangaea,” not “White People Don’t Know About Pangaea.” As a measure of what percentage of Americans truly understand continental drift, the poll is pretty useless; as an indication of how culture affects that understanding, it’s very illuminating.