通貨替代、價格調整與產出波動

Department of Economics Soochow University and Research Center for Humanities and Social Sciences Academia Sinica

本文建構一個包含質易財與非質易財的兩部門特定要素模型，在不 完全競爭市場的假定下，分析貨幣寬鬆對小型開放經濟商品相對價格、 民眾對不同通貨持有量及實質產出的影響。研究發現：如果國外通貨膨脹率不為零，則寬鬆的貨幣政策就不具中立性，即穩固狀態下實質變數（例如相對價格、消費、產出等）也會發生變動。其中非質易財相對價格是降或升，端視本國通貨和外國通貨究竟是毛替代或毛補充而定。一旦非貿易財相對價格變動，實質產出亦隨之變動，其變動方向則取決於商品市場需求價格彈性及兩部門工資差異的相對大小。由於在貨幣政策採行的瞬間，已經衝擊非貿易財相對價格且發生過度反應，故其動態行為即穩固狀態的變動會走相反的走勢，進而因商品和要素市場相對不完全性帶動實質產出呈現不同樣貌的調整時徑。

This paper incorporates the feature of imperfect competition in product and factor markets into a specific-factor two-sector (tradable and non-tradable goods) model to investigate the roles of currency substitution and market imperfections on the effects of monetary policy and on the output movements. It shows that the degree of currency substitution and the existence of foreign inflation are two crucial determinants in influencing the effects of monetary policy on the real exchange rate (hence the relative prices of non-tradable to tradable goods). The relative magnitude of the elasticities of demand for both goods and the wage differential influences critically the steady-state response and the dynamic path of output fluctuations. This dynamic general equilibrium model also shows that the impact of monetary policy on the real exchange rate (the relative prices of non-tradable to tradable goods) and the real output is greater than their steady-state changes. Therefore, it can be veriied that these relevant variables behave in an opposite movement to approach their new steady-state values in the transition period.