動態隨機一般均衡（DSGE）架構下之台灣最適貨幣政策分析

Optimal Monetary Policy for Taiwan: A Dynamic Stochastic General Equilibrium Framework

本文藉由比較在一具有銀行部門的動態隨機一般均衡（DSGE）模型中，採行貨幣成長率法則與泰勒法則下之福利水準來評估台灣的最適貨幣政策。研究結果顯示，對台灣而言，貨幣成長率法則較泰勒法則更能有效地促進經濟穩定而達到較高的福利水準。主要原因在於貨幣總量具有與消費直接相關的流動性效果，透過控制貨幣總量的成長率將可有效地降低通膨與產出的波動性。此結果在不同的模型設定下街成立，且與Teo（2009）在一DSGE模型下估計所得之台灣當前的貨幣政策大致上一致，但最適貨幣政策在穩定通貨膨脹率與匯率上的效果較佳。

The objective of this paper is to investigate the monetary policy of Taiwan by using a micro-based dynamic stochastic general equilibrium (DSGE) model with a banking sector. Because Taiwan’s central bank has claimed to use the M2 aggregate growth rate as the monetary target since 1992, this study essentially centers on the welfare assessments of the optimized money growth rate rule and the alternative Taylor-type interest rate rule. We find that the money growth rate rule plays a better job in stabilization and is welfare dominating over the interest rate rule for all types of real shocks. Due to the liquidity effects that the monetary aggregate supplies for consumption, controlling the growth rate of the monetary aggregate can successfully reduce both the inflation and output volatilities. The welfare superiority of the monetary aggregate rule holds for alternative specifications of the model, including the frictionless credit market, the lower international capital mobility and lower nominal rigidity. The current monetary policy, estimated by Teo (2009), follows in a similar fashion to the optimized monetary policy that this study suggests, but has smaller effects in stabilizing the CPI inflation and exchange rates. Reinforcing its endeavors in inflation and exchange rate stabilization can be welfare improving.