此篇論文研究當無通膨目標、存在固定通膨目標及央行宣示通膨目標之三種不同情況下，央行之最適貨幣政策。我們建立數個顯示不同通膨和產出比重之模型，並探討當央行偏離中位數投票者偏好時，對貨幣政策有何影響。 若社會福利函數中之產出的比重較重，在無通膨目標、存在固定通膨目標下，通膨偏誤皆較大。但央行宣示通膨目標時，無論通膨或產出比重較重，視其不同條件而定，通膨偏誤可能較大或較小。另外，央行偏離通膨目標的懲罰，罰責越重使央行宣告之通膨率對民眾預期通膨之影響可能越大，亦可能越小。 將央行偏離中位數投票者偏好之因素納入考量時，在無通膨目標、存在固定通膨目標下，社會福利函數中之通膨比重較重時，通膨偏誤仍較低，而央行宣示通膨目標時，通膨偏誤仍可能較大或較小。但引入央行偏離中位數投票者偏好時，在某些條件下，通膨偏誤可能進一步下降。 / The paper studies the central bank’s monetary policy under pure discretionary, noncontingent targeting and targeting with announcement. We construct models with different weight on inflation and output in the social welfare function. Furthermore, we introduce the central bank’s deviations from the preference of the medium voters into the models to show the effects on monetary policy. The inflation bias is larger when there is more weight on output in the social welfare function in the case of pure discretionary policy and noncontingent targeting. In the case of targeting with announcement, regardless of more weight on inflation or on output, the inflation bias is either larger or smaller under different conditions. Besides, a greater penalty on the central bank’s deviations from the inflation target may increase or decrease the effect of announcements on the public’s inflation expectations. With consideration of the central bank’s deviations from the preference of the medium voters, the inflation bias is still smaller when there’s more weight on inflation in the social welfare function in the case of pure discretionary policy and noncontingent targeting. In targeting with announcement, the inflation bias may still be larger or smaller. However, with the central bank’s deviations from the preference of the medium voters, the inflation bias can be reduced further under some conditions.

本文使用分量處理效果方法，分析通貨膨脹目標政策對通貨膨脹的影響。 依據Svensson (1997)與Orphanides and Wilcox (2002)的理論可知，當通貨膨脹低於目標區間時，通貨膨脹目標政策對通貨膨脹具有正向的效果；當通貨膨脹高於目標區間時，具有負向的效果；而當通貨膨脹位於目標區間時，效果微弱。本文利用1980年--2010年17個國家的年資料作實證分析。實證結果發現，通貨膨脹目標政策在不同分量的通貨膨脹下對通貨膨脹的影響有所不同。當通貨膨脹低的時候，通貨膨脹目標政策對通貨膨脹具有正向效果；然而，當通貨膨脹高的時候，具有負向效果，且隨著通貨膨脹的上升，負向效果有增強的趨勢。此結果與前述理論一致。 即使考慮刪去高通貨膨脹國家、將不同開發程度的國家分開討論、不同的資料期間和不同的政策開始時間，均得到類似的結果。

隨著美國次級房貸衝擊世界經濟的影響不斷擴大，各國政府對於全球景氣的提振，莫不推出各種拯救方案。同時，為使相關拯救政策的效果得以發揮，各國央行莫不競相調降基準利率，以減輕投資者與消費者的資金成本壓力，企求藉此增加企業的投資意願與民眾的消費慾望，進而促使經濟景氣得以反轉為多。然而，欲使一國貨幣政策發揮其效果，除了社會大眾對於通貨膨脹預期的心理是否可以獲得消弭外，更重要的是央行貨幣政策傳遞管道是否暢通，是否對於整體經濟情勢仍具有相當的控制能力。而這些條件是否可以達成，而使央行貨幣政策確實可以發揮功效，其最主要的關鍵點除了與其所採行的貨幣運作機制有密切關係外，央行的獨立性、權責性與透明性的良窳更是具有決定性的因素。 然而，就臺灣而言，我國中央銀行法自一九七九年重新訂定後，僅於民國一九九七年大幅修訂，且於二ＯＯ二年時小幅修訂部分條文。但面對目前金融情勢變化快速與國內政治局勢的動盪，條文中對於有關央行獨立性地位的確認與央行權責性暨透明性的提昇等等現代化中央銀行所需具備的前提要件，卻似乎規範不甚明確。加以面對因金融自由化所造成市場中貨幣定義的模糊，以及貨幣目標制下政策效率不彰的困境，對於目前仍採行貨幣目標制做為政策執行架構的我國央行而言，其是否擁有其他可行的因應方式與選擇？是否需要追隨世界金融先進國家的腳步，更改目前的貨幣運作機制？是否通貨膨脹目標制對我國央行而言，具有執行上的絕對優勢？我國央行是否已經具備執行此項貨幣機制的相關必要條件？這些議題在國內相關文獻的探討中尚屬進一步探索的領域。故本文希冀透過對於我國央行獨立性、權責性、透明性以及其他主客觀經濟情勢的重新檢視，提出面臨的問題點以及可行的解決方案，以增進我國貨幣政策執行的有效性。 / With the more impacts on the economics in the world from the shocks of subprime-mortgage in America, many policies were proposed from every government to make the economic return the normal situation. For strengthening the effects of these policies, many central banks announced to cut the key interest rates. Because they wish could lighten the enterprises’ and consumers ‘costs of the capital by these policies, and then make them increasing the desires of the investments and consumptions to let the whole economic situations back to good ones. However, whether the monetary policies really have the effects or not, it depends on many elements, including if the central bank eliminates the expectations of inflation of the public or not, the monetary transmission channels could work successfully or not, the central bank could control the key economic variables or not and others seriously. Nevertheless, the monetary policy mechanism of this country, the level of independence, accountability and transparency of the central bank are the key factors that could influence these conditions work valid or not. In Taiwan, The Central Bank of China Act was amended in 1979. In 1997, this law was modify widely and revised few articles in 2002. However, these articles were not being considered how to make affirm the independence position of the central bank, and how to improve the accountability and transparency of the central bank to make the CBC meet the conditions of the modern central bank. Beside this, in the difficult status of the blurred definition of the money and of weakly effectiveness of the monetary policy in the monetary targeting framework, whether the CBC which still adopts the monetary targeting to be the main monetary policy mechanism has any choices to break these problems or not ? Whether the CBC needs to follow the advanced countries to alter the monetary policy mechanism to the inflation targeting framework? Whether the CBC could get more benefits to adopt the inflation targeting? And whether the CBC could meet all the preconditions of the inflation targeting? These issues are so important but not to be discussed in domestic academic literatures. Therefore we want to review the level of the independence, accountability and transparency of the CBC and other economic conditions to see the problems of the monetary policy mechanism in Taiwan. And then, we will provide the feasible suggestions to these problems to improve our monetary policy effectiveness.