台灣貨幣政策法則之檢視

ASSESSING MONETARY POLICY IN TAIWAN

本文的目的是分析台灣1981年以來的貨幣政策法則(monetary policy rule)。透過估計貨幣政策反應函數，我們有如下的發現：(1)1981～1997 年，台灣央行的貨幣政策可用貨幣成長率法則(money growth rule)予以刻劃，反之，1998～2008年，則以利率法則(interest rate rule)較能適切說明台灣貨幣政策。(2)台灣央行於1999年後可能採用不對稱的非線性利率法則。亦即新台幣升值時，干預外匯市場，採寬鬆貨幣政策；新台幣貶值時，央行不阻貶，甚或可能推波助瀾地助貶。

This paper investigates monetary policy in Taiwan since 1981. We estimate the monetary policy reaction functions, including the money growth rule (McCallum Rule) and the interest rate rule (Taylor Rule). The following empirical findings are obtained. First, it is suggested that a money growth rule is more appropriate to describe the monetary policy reaction from 1981–1997, while an interest rate rule seems to have a better fit for the period from 1998 to 2008. Second, there may exist nonlinearity in the interest rate rule after 1998. The policy rule switches between different regimes, which depends on whether the NT dollar/US dollar exchange rates appreciate or depreciate.