利率目標區與貨幣供給目標區之抉擇

Abstract

本文承襲Fang and Lai(2002}的模型架構， 同時運用數學推導及幾何圖解的方法， 討論利率目標區與貨幣供給目標區對於相關總體經濟變數 (包括產出及商品價格) 的影響效果。 本文的結論可以歸納如下： (1)當經濟體系面臨總合供給面的隨機衝擊時， 利率目標區雖能穩定產出， 但卻使得商品價格的波動更為劇烈； 相反地， 貨幣供給目標區則是能夠穩定商品價格， 但無法穩定產出。 故若貨幣當局選擇以穩定產出為優先， 則應採行利率目標區； 而若貨幣當局較重視商品價格的穩定， 則應採行貨幣供給目標區。 (2)若經濟體系面臨的隨機衝擊是來自於商品需求面， 利率目標區的宣示只會加劇產出及商品價格的波動； 而貨幣供給目標區則對產出及商品價格皆具有蜜月效果。 故貨幣當局應採行貨幣供給目標區。 (3)當經濟體系面臨貨幣需求面的隨機衝擊時， 利率目標區的宣示可以同時穩定產出及商品價格； 然而， 貨幣供給目標區則加劇產出及商品價格的波動。 因此， 貨幣當局應採行利率目標區。 (4)不論經濟體系面臨的隨機衝擊來源為何， 實施利率目標區只會加劇利率的波動； 而貨幣供給目標區對於貨幣供給則皆具有蜜月效果。

Based on the Fang and Lai (2002) model, this thesis analyzes the stabilizing performance of target zones (including the money supply target zones and the interest rate target zones) on macroeconomic variables (including output and commodity prices). Several central conclusions emerge from the analysis: (1) When the economy faces aggregate supply disturbances, the interest rate target zones tend to stabilize output and destabilize commodity prices. On the contrary, the money supply target zones tend to lower the variability of commodity prices, but raise the variability of output. Thus, if the monetary authorities choose to stabilize output, they should adopt the interest rate target zones. On the other hand, the monetary authorities should adopt the money supply target zones when they choose to stabilize commodity prices. (2) If the economy experiences demand shocks, the announcement that the monetary authorities intend to defend the interest rate target zones raises the volatility of both output and commodity prices. However, the money supply target zones tend to lower the variability of both output and commodity prices. As a result, the monetary authorities should adopt the money supply target zones. (3) When shocks hit the economy through the money demand side, the interest rate target zones stabilize both output and commodity prices. The money supply target zones, however, destabilize both output and commodity prices. Therefore, the monetary authorities should choose the interest rate target zones.