1. Everyone-a-banker or the Ideal Credit Acceptance Game: Theory and Evidence. (joint with Juergen Huber and Martin Shubik) 2. Three Minimal Strategic Market Games: Theory and Experimental Evidence. (joint with Juergen Huber and Martin Shubik)

東京大学経済学研究科棟 3階 第3教室

Shyam Sunder 氏
Yale University

1) Is personal credit issued by participants sufficient to operate an economy efficiently, with no outside or government money? Sorin (1995) constructed a strategic market game to prove that this is possible. We conduct an experimental game in which each agent issues her own IOUs and a costless efficient clearinghouse adjusts the exchange rates among them so the markets always clear. The results suggest that if the information system and clearing are so good as to preclude moral hazard, any form of information asymmetry, or need for trust, the economy operates efficiently at any price level without government money. Conversely, perhaps explanations for prevalence of government money should be sought in either the above mentioned frictions or our unwillingness to experiment with innovation.

2) In this experiment we examine the performance of three minimal strategic market games relative to theoretical predictions. These models of a closed exchange economy with monetary and financial structures have limited amounts of cash to facilitate transactions. Subsequent experiments will deal with credit limitations, banking and credit, the role of clearinghouses and the possibility for the universal issue of credit by individuals. In theory, with enough money the non-cooperative equilibria should converge to the respective competitive equilibria as the number of players increases. Since general equilibrium theory abstracts away from the market mechanism, it makes no predictions about how the paths of convergence to the CE may differ across market mechanisms. GE allows no role for money or credit. In contrast to most market experiments conducted in open or partial equilibrium settings, we report on closed settings that include feedbacks. Laboratory examination of the three market mechanisms reveals convergence to CE with increasing number of players. It also reveals significant differences in the convergence paths across the mechanisms, suggesting that to the extent deviations from CE are of interest (either because the number of players in the environment of substantive interest is small, or because disequilibrium behavior itself is of substantive interest), theoretical abstraction from the market mechanisms has been taken too far. For example, the oligopoly effect of feedback from buying a good that the player is endowed with is missed. Inclusion of mechanism differences into theory would help us understand markets better.

備考: Microworkshop と共催