開放體系下匯率區間政策的穩定性與政策效果

本文旨在探討，在開放體系下，一國之匯率目標區（exchange rate target zone）政策是否能達到長期穩定狀態，並分析此匯率政策對實質利率、產出缺口及失業率的影響。本文建構一對稱的兩國模型，並引入適應性學習預期穩定概念，假設各國政府完全理性預期個體部門的行為，而個體部門採有限理性預期（bounded rationality）下，得到政府匯率區間政策的長期穩定條件。本文亦探討兩國政府貨幣政策的互動會對兩國的總體實質面產生哪些影響，本文將分別分析在兩國採合作的貨幣政策（coordination）、非合作貨幣政策（noncoordination）領導與跟隨者模型（leader-follower）下，各種架構下的長期穩定條件有何差異。本文並將透過引入極小狀態變異下理性預期均衡（minima-state-variation rational expectation equilibrium, MSVREE）觀念，以檢驗在考慮匯率區間（或匯率趨帶；exchange rate band）下，民眾採適應性學習過程所得到的均衡實質匯率在長期是否能達到穩定狀態。

關鍵字

匯率目標區；適應性學習；開放經濟體

並列摘要

This paper aims to explore whether, in an open economy, a country’s exchange rate target zone policy can achieve its steady state value in long term, and to analyze the effects of exchange rate policy on the real interest rates, output gap and unemployment rates. I construct a symmetric two-country model, and introduce the concept of adaptive learning in my model. Assuming that governments rationally expect the behavior of agents, and agents adopt the way of bounded rationality, then, we can obtain the exchange rate target zone policy of the government of the long term steady state. This paper also examines the interaction of monetary policy between the two countries. I will analyze this issue under coordination, non-coordination, and leader-follower, and find out the stability conditions of the exchange rate target zone policy long term stable conditions. Moreover, this study introduces the concept of minima-state-variation rational expectation equilibrium, MSVREE, to examine whether the long-term equilibrium of the real exchange rate would be achieved where people face the exchange rate band policy and make decisions by applying the adaptive learning process.