貨幣政策對異質廠商型態之小型開放經濟的影響效果

Monetary Policy Effects in a Small Open Economy with Heterogeneous Firms

本研究探討在具有廠商異質性特徵的小型開放經濟體中，貨幣政策對外部衝擊的福利效果。透過納入Rotemberg型價格調整成本的動態隨機一般均衡（DSGE）模型，分析從傳統貨幣目標到擴展型泰勒法則等五種貨幣政策規則。研究發現，廠商異質性透過市場進入/退出與出口決策，顯著影響政策傳導效果。各種衝擊（技術、外部需求、通膨及利率）對匯率、廠商數量和產出水準產生不同影響。結果顯示，在應對外部衝擊時，貨幣數量法則比利率法則更能有效穩定經濟變數;而在貨幣政策中考慮匯率穩定性則能提升小型開放經濟體的福利。這些研究發現對於台灣等經濟體特別具有參考價值，因為政策效果很大程度上取決於廠商異質性的影響。

This study investigates the welfare effects of monetary policy responses to external shocks in a small open economy characterized by firm heterogeneity. Through a Dynamic Stochastic General Equilibrium (DSGE) model incorporating Rotemberg-type price adjustment costs, it analyzes five monetary policy rules, ranging from traditional monetary targeting to extended Taylor rules. The findings reveal that firm heterogeneity significantly influences policy transmission through market entry/exit and export decisions. Various shocks (technological, external demand, inflation, and interest rates) yield distinct impacts on exchange rates, firm numbers, and output levels. The results indicate that money quantity rules are more effective than interest rate rules in stabilizing economic variables against external shocks, while considering exchange rate stability in monetary policy enhances welfare for small open economies. These insights are particularly relevant for economies like Taiwan, where policy effectiveness largely depends on understanding and accounting for firm-level heterogeneity.