This paper analyzes the optimal time to abandon a fixed exchange rate regime in response to a fiscal shock that renders the peg unsustainable. We consider three variants of an optimization-based first-generation speculative attack model. In the first variant there are exogenous costs of...

The influential Krugman-Flood-Garber (KFG) model of balance of payment crises assumes that a fixed exchange rate is abandoned if and only if international reserves reach a critical threshold value. From a positive standpoint, the KFG rule is at odds with many episodes in which the central bank...