Second Generation Models of Currency Crises

Until the beginning of the 1990s, currency crises were typically analyzed within the framework of a generation of models that assumed that the foreign exchange reserves of a country that was running a fixed exchange rate policy were falling (because the government was running a deficit on its budget that was financed by printing money). When the foreign exchange reserves reached a lower bound, a speculative attack on the fixed exchange rate was launched. Today, this theory is no longer the benchmark when explaining the occurrence of a currency crisis. Actually, a new generation of models that seeks to take explicitly into account the costs and benefits associated with the maintenance of a fixed exchange rate has emerged. This paper surveys these ‘second generation models of currency crises’. This generation of models emphasizes that it is an endogenous decision if a government chooses to abandon a policy of fixed exchange rates. The survey pays special attention to the fact that the second generation of currency crises models often generates multiple equilibria for the rate of devaluation given one state of the economic fundamentals. A currency crisis can thus occur even if no secular trend in economic fundamentals can be identified, as in recent currency crises.