浮動還是固定?零利率之下的匯率政策

Abstract

當一國的利率低至零利率下限時，稱此國掉入流動性陷阱。本文針對一個具有金融摩擦與流動性陷阱的經濟體，比較浮動匯率與固定匯率之差異。我們分別檢視以下三種情況：一般情形的浮動匯率制度、流動性陷阱中的浮動匯率制度、固定匯率制度。結果顯示，固定匯率比掉入流動性陷阱的浮動匯率更能穩定經濟體；而當一定程度的金融摩擦存在時，一般情形的浮動匯率制度表現則劣於可實行負利率的固定匯率制度。

The liquidity trap refers to the situation where countries have their interest rates near the zero lower bound. This paper compares whether a floating exchange rate or a fixed exchange rate is more preferable under liquidity traps for the world economy with financial frictions. We specifically examine three cases: a floating-rate system in normal times, a floating-rate system in liquidity traps, and a fixed-rate system. Our results indicate that a fixed exchange rate performs better than a floating one in liquidity traps, and that the floating-rate system in a normal situation may be inferior to the fixed-rate system with negative interest rates if some financial frictions exist.