Saturday, January 11, 2014

Economics And Physics: A Disanalogy

John Scalzi's Cat Looks At A Hugo Award

Suppose you criticize current neoclassical teaching in introductory microeconomics. A defender might reply that it is common to teach incorrect models in introductory classes. Only when the students have that background can they go on to the more sophisticated teaching. For example, physicists teach Newtonian mechanics. They do not start with quantum dynamics and the special and general theories of relativity.

I doubt this defense. Physics can roughly state the domain of applicability of Newtonian physics - medium size dry goods. Physicists have had empirical success within that domain to an astonishing degree of precision. I doubt economists can point to a success where they can notice tiny variations from their predictions analogous to the deviation of the perihelion of the orbit of Mercury of 43 seconds of arc per century or the deflection of the location of stars observed during a solar eclipse. But I do not want to argue about the relative empirical success of simplified theories in economics and physics.

Rather, I want to point out a large difference in the status of such introductory theories in popular culture. A large body of literature exists, popular among schoolchildren and others, pointing out the limitations of Newtonian mechanics. I refer to Science Fiction. The speed limit imposed by the speed of light, for example, is a common trope in SF. It is true that some authors do not hold to it. But they often insist that when their characters violate the constraints of the theory, they utter some jargon: "tachyon nexus", "wormhole", "space warp". Furthermore, SF authors tell many stories where these limits play out, for example, with generation ships that may accelerate and decelerate and in which the crew are quite aware of the difference between their slowed-down local time and the time of the folks back on planet earth. I think that SF back in the forties and fifties may have been more prone to contain lectures about these matters. Nevertheless, I think many students of introductory physics are aware that the truths of Newtonian theory, which they can see played out in the laboratory, do not extend to all of the universe of physics.

I suggest even if you can find accounts in popular culture of, say, implications of game theory inconsistent with introductory microeconomics teaching, you cannot find something as popular and pervasive for economics as SF is for physics. The culture resists somebody preaching physics 101 as an explanation for everything physical.

1 comment:

Emil Bakkum said...

The German economist Gustav Schmoller of the Historical School thought that the economic science is not yet ready for deductive theories. I think that he is right. On the other hand this means that economics can only be common sense, which is vulnerable for power-based manipulations. Probably it would be better to teach the neoclassical theory only in the third year or so. The first study years could be devoted to courses about the real economy, industrial organization and econometrics.