台灣在1988年後歷經金融改革與貨幣政策轉變, 促使其全球化程度增加並降低通貨膨脹波動,這些改變可能導致菲利普曲線產生結構性變化。為檢視此現象, 本文建構一個小型開放體系之隨機動態全面均衡模型並導出新凱因斯菲利普曲線,藉由最大概似法估計模型的結構參數了解曲線變化。實證結果顯示1988年以後, 除金融改革因素外, 貨幣政策轉變對物價產生的穩定效果, 亦是改變台灣菲利普曲線斜率的主因。為了確認上述結論, 進一步使用狀態空間模型, AR(p) 模型以及動差法建構縮減式菲利普曲線, 檢視其斜率改變原因,發現結論與最大概似估計法一致。另外藉由變異數分解,我們發現台灣在1988年之前的景氣波動主要受到貨幣政策與技術進步的影響, 1988年之後主要影響因素則為生產力與投資效率。

Taiwan has experienced finance reform and monetary policy change since 1988 and seen an increased level of globalization and reduced volatility of inflation. These changesmay lead to a structural change of theNew-Keynesian Phillips curve. This paper constructs a small open stochastic general equilibrium model and derives the New-Keynesian Phillips curve to examine the effects of finance reform and monetary policy change on the slope of the curve. The results show that besides financial reform, the monetary policy change which stabilized the price level was a main factor increasing slack in the New-Keynesian Phillips curve after 1988. To confirm the conclusions above, we employ a state-space model and AR(p) to obtain expected inflation, and then estimate the slope of the reduced form Phillips curve. This supports the above conclusion. Furthermore, variance decomposition analysis shows that monetary policy shocks and technology shocks were the main contributors to the business cycle before 1988, while investment efficiency shocks and technology shocks became the main factors after 1988.