In markets with imperfect information and heterogeneity, the information technology affects the rate at which agents meet, which in turn affects the distribution of production technologies across firms. We show that in models for such markets there are typically multiple equilibria because...

Instrumental variable estimation requires untestable exclusion restrictions. With policy effects on individual outcomes, there is typically a time interval between the moment the agent realizes that he may be exposed to the policy and the actual exposure or the announcement of the actual...