The Dynamics of General Equilibrium: A Comment on Professor Gintis

This is a comment on Gintis (2007, 'The Dynamics of General Equilibrium', Economic Journal 117 (523) , 1280–1309), who provides an agent-based model of a Walrasian economy where the tâtonnement is replaced by imitation. His simulations show that the economy converges to the Walrasian equilibrium. Gintis concludes that 1) his stability results provide some justification for the importance placed upon the Walrasian model, and 2) models allowing agents to imitate successful others lead to an economy with a reasonable level of stability and efficiency. Since these conclusions appear to be intended as general, we caution that Gintis's findings can only be accepted for Walrasian models without capital goods; in models with capital goods imitation-based adjustments alter the equilibrium's data (which makes the demonstration of stability impossible) and raise other important problems (absent from Gintis's simulations) still awaiting exploration.