小型開放經濟體系下之政府公債與最適貨幣政策及財政政策

Abstract

最近的歐洲債務危機顯示了貨幣政策與財政政策之間的緊密關係。本研究的目的即在於探討在一小型開放經濟體系中之政府公債、最適貨幣政策與財政政策。藉由一小型開放經濟，且具有三種市場不完全機制 (獨占性競爭、名目僵固性與所得稅) 的動態隨機一般均衡 (DSGE) 模型，我們將要探討相關的公債議題 (Adam (2011))。在此一開放經濟體制之下，我們將會特別著重在經濟開放性對於政府公債的影響。 此研究計畫之研究重點如下： 1. 我們將會以模擬校對(calibration)來進行量化分析。主要會採取目前有債務危機的歐元區國家（希臘、愛爾蘭、義大利、西班牙）與亞洲國家(台灣、香港、新加坡、韓國) 之資料來進行模擬校對。 2. 在此小型開放經濟下，我們將要探討在不同的期初公債水準下，主要的總體變數面對負向衝擊時的動態調整過程。我們特別要探討期初公債所得比(debt-GDP ratio)對於匯率動態調整的影響。 3. 我們亦想探討貿易開放與資本開放程度對於政府公債所得比的影響。 4. 面對外來衝擊時，在固定匯率下，相較於彈性匯率，公債所得比的動態調整會如何變化？

The objective of this research is to examine the public debts and welfare-optimizing monetary and fiscal policies in a small open economy, in line with the recent debate on the European debt crisis. We will use a small-open-economy dynamic stochastic general equilibrium (DSGE) model with three types of market distortions including monopolistic competition, nominal rigidity, and distortionary income tax to examine similar issues on public debts and optimal monetary and fiscal policies that Adam (2011) brings up for a closed economy, but with emphases on the effects of economic openness on the public debts. The key points of this research include: 1. In the benchmark calibration, we will calibrate for the European countries including Greece, Italy, Ireland and Spain. We will also calibrate for the Asian countries including Taiwan, Hong Kong, Singapore and Korea to obtain policy implications for these highly open economies where the exchange rate movement can play a significant role. 2. Under this small open economy framework, we would like to examine how the macroeconomic dynamics, particularly government expenditure, tax revenue, the debt-GDP ratio and the exchange rate may differ under the optimal monetary and fiscal policies, given different initial levels of public debts. We will emphasize how the outstanding debt-GDP ratio can affect the exchange rate movement which is normally the primary concern of the central bank in a small, highly open, economy. 3. How will the dynamics of the debt-GDP ratio differ under different degrees of trade and financial openness? 4. How will the dynamics of debt-GDP ratio change under a fixed exchange rate regime?