通貨替代、價格調整與產出波動

本文建構一個包含貿易財與非貿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。其中非貿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，其變動的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，故其動態行為與穩固狀態的變動會呈相反的走勢，進而因商品和要素市場的相對不完全性帶動實質產出呈現不同樣貌的調整時徑。

關鍵字

不完全競爭；通貨替代；相對價格；產出波動

並列摘要

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 verified that these relevant variables behave in an opposite movement to approach their new steady-state values in the transition period.