In repeated normal-form games, simple penal codes (Abreu 1986, 1988) permit an elegant characterization of the set of subgame-perfect outcomes. We show that the logic of simple penal codes fails in repeated extensive-form games. We provide two examples illustrating that a subgame-perfect outcome...

Do large investors increase the vulnerability of a country to speculative attacks in the foreign exchange markets? To address this issue, we build a model of currency crises where a single large investor and a continuum of small investors independently decide whether to attack a currency based...

Even though self-fulfilling currency attacks lead to multiple equilibria when fundamentals are common knowledge, we demonstrate the uniqueness of equilibrium when speculators face a small amount of noise on their signals about the fundamentals. This unique equilibrium depends not only on the...

The swiftness and devastating impact of recent financial crises have taken many market participants by surprise and pose challenges for economists seeking a theory of the onset of a crisis. We propose such a theory based on two features. The actions of diverse economic actors which undermine the...