We investigate the role of networks of military alliances in preventing or encouraging wars between groups of countries …, we show that there do not exist any networks that are stable against the addition and deletion of alliances. We then show …

Recession. I next develop a heterogeneous firm model with Bayesian learning and uncertainty shocks to study the aggregate …'s (1982) model of learning in a setting where each firm gradually learns about its own productivity, and each occasionally … experiences a shock forcing it to start learning afresh. Firms differ in their information; more informed firms have lower …