Transactions Costs and Nonlinear Adjustment in Real Exchange Rates; An Empirical Investigation
发现交易成本会导致实际汇率非线性调整，传统协整检验可能低估长期购买力平价，而指数平滑转换自回归模型能更好捕捉均值回复行为，解释以往研究矛盾。
Equilibrium models of real exchange rate determination in the presence of transactions costs imply a nonlinear adjustment process toward purchasing power parity (PPP). Conventional cointegration tests, which ignore the effect of transactions costs, may be biased against the long-run PPP hypothesis. The authors' results, using both monthly data for the interwar period and annual data spanning two countries, clearly reject the linear framework in favor of an exponential smooth transition autoregressive process. The systematic pattern in the estimates of the nonlinear models provides strong evidence of mean-reverting behavior for PPP deviations and helps explain the mixed results of previous studies. Copyright 1997 by the University of Chicago.