AGAINST THE HOMO OECONOMICUS

Mark Buchanan introduces the new disciple of social physics

By Frank Ufen

[This book review of Mark Buchanan’s “Why the Rich Become Richer and Richer. New Discoveries from Social Physics,” 262 pages, Campus Verlag, Frankfurt and New York, 2008 published in: Junge Welt, 8/14/2008 is translated from the German on the World Wide Web, http://www.jungewelt.de/2008/08-14/005.php?print=1.]




One can imagine a great number of persons without the least differences. All would have the same character, the same temperament and the same intelligence quotients. All would enjoy the same knowledge, the same abilities and the same investment skill. If every person were given 00 for stock purchases and the rise and fall of stock prices were completely accidental or a matter of chance, what would happen? Two physicists, Jean-Philippe Bouchaud and Marc Mezard simulated this scenario on the computer and came to an astonishing conclusion: most investors would either gain small amounts or lose. Some would go bankrupt. Only a few would make a great haul. Those already rich – who have massive capital and manifold possibilities for investments – would have the best chances for increasing their wealth.

In the eyes of the American physicist and scientific journalist Mark Buchanan, this experiment demonstrates the gap between poor and rich inevitably grew in the course of liberalizing markets and that special human abilities were often irrelevant. Regarding actions and reactions of large groups of people, complex models of self-organization would arise through simple feedback processes. Researching this constantly recurring pattern is the task of a new discipline that Buchanan calls “social physics.” Social physics depends on physics and mathematics as well as sociology, social psychology and economics. Buchanan vehemently rejects the interpretation of the Homo oeconomicus defended by the neoclassical economist Gary Becker.

The Homo oeconomicus supposedly acts completely rationally and makes his decisions in a social vacuum. The Nobel Prize winner for economics Gary Becker claims, for example, that a careful cost-benefit analysis precedes every calculation. Buchanan reproaches Becker for replacing persons of flesh and blood with pseudo-subjects without values, history and society. From Buchanan’s perspective, people constantly try to gain information about each other, particularly in situations of crises and dangers. According to him, evolution did not intend the human brain for complicated calculations and evaluation of statistical probabilities – an indispensable prerequisite for a careful cost-benefit analysis. On the other hand, Buchanan claims social physics can help explain elementary phenomena from the genesis of trends, rumors, transportation status, stock market crashes and revolutions to altruism, moral standards and God. Social physics can only do partial justice to this ambitious claim. Buchanan could be criticized for tending to oversimplification and grappling too little with details. Nevertheless his book is original and informative.