Experimental Markets and Chamberlin's Excess Trading Conjecture

Ted Bergstrom, University of California, Santa Barbara

Abstract

Edward Chamberlin conjectured that the number of trades in realistic trading systems is likely to exceed that predicted by competitive equilibrium theory. He supported this conjecture by data from a large number of classroom experiments and with a plausible argument based on a numerical example. This paper states and proves a theorem that supports and illuminates Chamberlin's intuition, supplies examples of trading processes that lead to excess trading, and presents some additional experimental evidence.