Mark D. White

This Non Sequitur comic appeared in this morning's newspaper (and online):

Ha ha, we get it, economists are stubborn theorists who are holed up in their ivory towers with no sense of the real world, situational context, or empirical circumstances.

I almost tweeted this comic, as I do with two or three strips each morning I find worth tweeting (low bar there, I admit). But I thought twice and in the end decided not to, because I didn't want to endorse its caricature of economists. As with all caricature, it takes a kernel of truth and blows it out of proportion--very clever when done right, but it reflects poorly on the caricaturist when it's done wrong, as in this case.

In economics--especially macroeconomics--theories can rarely be disproven or discredited based on evidence, because the space between general theories and specific evidence is far too great and rife with complicating factors. If a general theory is implemented at a particular time, in particular circumstances, in a particular way, and in a particular political context, and it doesn't work, how do you know whether to blame the theory or any one of the myriad details that interfered with its operation? At the most, you can argue that the theory was not implemented properly because the particularities of the sitation were not accounted for properly. But you cannot conclude that the theory is incorrect until it fails in many situations, at many times, etc.

Of course, we can easily assume that the cartoon addresses the current economic malaise and/or attempts to remedy it (though the metaphor with getting people over a crevice grossly misrepresents the enormous complexity of the macroeconomy and the difficulty with applying any theories to it). People on each side of the economic argument over the role of the state can claim that their theory wasn't adequately tested: free-market economists can deny responsibility for the crisis because the housing and financial markets were hardly free from government interference, and Keynesians can deny responsibility for the continued downturn by saying that the stimulus just wasn't big enough.

In the end, theories in economics--especially macroeconomics--must be judged by their internal logic, given the tremendous (perhaps insurmountable) difficulty with relying on empirical evidence to judge them. Given the million things that could go wrong when implementing the best theory in an imperfect world--or the million things that could make even the worst theory look effective--evidence just doesn't cut it. What evidence can do, however, is help economists and policymakers to finetune the implementation of their theories.

In the end, poor results from implementing a logically sound theory do not discredit it--they just demand better implementation.