Tuesday, March 22, 2011

"Is economics a science?" and other silly question

There are few debates more annoying than the perennial economics-as-a-science discussion. For one thing, it almost invariably prompts someone to bring out the old "look at our math" argument, apparently unaware that unnecessarily complicated mathematics is a standard trait of pseudo-science (just try talking to an astrologer or a relativity denier).

Worse yet is the idea that being a scientist buys you a certain credibility, that your pronouncements should automatically be given weight because of the lab coat. (There's a reason the FDA doesn't let actors in drug ads dress as doctors any more.) A well-reasoned, well-supported argument from a historian still trumps a stupid one from a scientist.

But if you have to make the classification, it seems obvious to me that economics is a social science, albeit one facing some special challenges (as discussed in this previous post):
Compared to their nearest neighbors, film criticism and economics (particularly macroeconomics) are both difficult, messy fields. Films are collaborative efforts where individual contributions defy attribution and creative decisions often can't be distinguished from accidents of filming. Worse yet, most films are the product of large corporations which means that dozens of VPs and executives might have played a role (sometimes an appallingly large one) in determining what got to the screen.

Economists face a comparably daunting task. Unlike researchers in the hard sciences, they have to deal with messiness of human behavior. Unlike psychologists, microeconomists have few opportunities to perform randomized trials and macroeconomists have none whatsoever. Finally, unlike any other researchers in any other field, economists face a massive problem with deliberate feedback. It is true that subjects in psychological and sociological studies might be aware of and influenced by the results of previous studies but in economics, most of the major players are consciously modifying their behavior based on economic research. It is as if the white mice got together before every experiment and did a literature search. ("Well, there's our problem. We should have been pulling the black lever.")

Faced with all this confusion, film scholars and economists (at least, macroeconomists) both reached the same inevitable conclusion: they would have to rely on broader, stronger assumptions than those colleagues in adjacent fields were using. This does not apply simply to auteurists and freshwater economists. Anyone who does any work in these fields will have to start with some sweeping and unprovable statements about how the world works. Auteurists and freshwater economists just took this idea to its logical conclusion and built their work on the simplest and most elegant assumptions possible, like Euclid demonstrating every aspect of shape and measure using only five little postulates.

(Except, of course, Euclid didn't. His set of postulates didn't actually support his conclusions. The world would have to wait for Hilbert to come up with a set that did. The question of whether economists need a Hilbert will have to wait for another day.)
Having said that, the current debate is several notches above what I expected. Brad DeLong is asking some tough questions about economics not just as a science but as a discipline and we're getting some interesting and insightful comments from scientists in other fields.

This time, it's a discussion worth following.

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