Stabilization Policies in Open Economies
回顾了浮动汇率制度下简单模型的假设（如购买力平价、利率平价）与实证证据的冲突，指出基于这些假设的模型不可靠，并讨论了强调资产市场和预期的模型作为替代，但预测能力仍不足。
Before the shift in 1973 to floating exchange rates between major currencies, the most widely held views of proponents of floating exchange rates on how economies would behave in such a regime, and what effects monetary and fiscal measures would have at home and abroad were based on simple models. This simplicity was achieved by imposing various strong a priori assumptions. The most common and crucial assumptions were continuous equilibrium in all markets, stable money demand, purchasing power parity, and uncovered interest parity (equality between interest rate differentials and expected changes in exchange rates). While these assumptions were not necessarily expected to hold exactly at all times, they were deemed strong tendencies. Ten years of floating exchange rates have given ample reason to doubt the utility of models based on these assumptions.1 The clash between theory and evidence leaves analytical economists without a firm foundation from which to draw policy conclusions. The one major counter to this eroding foundation has been the development of models which emphasize the role of asset markets, and hence of expectations, for exchange rate determination and for macroeconomic behavior more generally. But expectations are not well enough understood to provide models with good records of prediction, which can be used as reliable guides to policymaking.