中國的貨幣政策該如何釘住物價？ －以人民幣匯率政策為例兼論對房產價格的影響

Abstract

金融海嘯後，許多文獻開始檢討現行貨幣政策是否失靈，以及是否該為貨幣政策注入新的活水，維持價格水平（price-level）穩定的政策目標於是呼聲再起。本文以中國作為研究對象，依據價格水平目標制的理念，為其構建可行的貨幣政策操作方式與目標，並觀察此操作對房價的外溢效果。 本文首先綜覽相關研究對物價穩定目標的討論，包括通膨目標制和價格水平目標制之間的取捨，接著整理中國自2005年匯改後，將人民幣釘住一籃子貨幣的政策，最後將研究核心聚焦在「以匯率政策作為釘住價格水平的操作手法」，而這樣的研究設計則受到張五常的啟發。研究設計如下：從購買力平價學說的公式出發，本文計算出釘住固定價格水平、釘住通膨率2%和釘住中國PPI起伏等三種考慮物價穩定的名目有效匯率指數（NEER），並將此三者與未考慮物價穩定的有效匯率指數市場現況做一對比。實證結果為：（一）三種考慮物價的匯率指數走勢和市場現況相反，前者的政策意涵是執行相對中性的貨幣政策，而後者則是需要執行寬鬆貨幣政策；（二）三種考慮物價的匯率指數標準差較小，表示在釘住物價同時兼能收匯率穩定之效。因此，作為政策建議，本文認為釘住物價的匯率政策值得嘗試。 然而，依據不同指數結果所執行的貨幣政策是否對其他經濟領域產生外溢效果？本文圍繞房價議題，從Poterba的房價使用者成本理論模型出發，並加入自行計算的NEER變項，迴歸結果顯示，NEER落後項對全國和部分一線城市房價的影響為顯著為正，證實由匯率政策所引發的貨幣供給調控，的確會傳遞到房價上，貨幣供給增加和房價上升實為一體兩面；另外，有進行物價考慮操作時，迴歸係數顯示釘住固定價格水平和釘住通膨率2%的反事實設計對北京、上海、深圳三座一線城市房價上升的正向影響小於政策現況，但對廣州和全國房價影響則較大，說明採取不同釘住目標的貨幣政策對不同地區房價的影響效果各異，很難有一致性的政策結果。未來在設計貨幣政策的釘住目標時，當局必須思考全國性貨幣政策對不同地區的不同潛在影響。

After the 2008 financial crisis, many studies have begun to review monetary policy and attempted to find new paths or make adjustments to the current policy framework. Price level targeting is one such approach. In this paper, we selected China’s transforming exchange rate policy to study and calculate the nominal effective exchange rate (NEER) indexes of fixed price level, 2% inflation, and PPI-pegging where domestic price stability was considered in different ways based on the theory of Purchasing Power Parity. Also, we compared these “price-stability” NEER with the current NEER results without consideration of price stability. The proposed approach led to two important findings: 1) NEER indexes considering price stability point to a relatively neutral monetary policy while the current NEER results demonstrate an easing policy, one which Chinese authorities have already implemented recently, meaning that the monetary policy conducted has run substantially counter to the idea of price stability; 2) the standard deviation of the former price-stability NEER indexes was smaller than that of the current NEER results, meaning that these price targeting practices could also stabilize the exchange rate. Thus, we suggest that using the RMB exchange rate as a tool to implement RMB price level targeting is a feasible method. Furthermore, when we extended those two groups of NEER indexes to another hot issue – the housing boom effect in China, the regression model based on the theory of Poterba (1984) turned out that the lag period of the NEER indexes had a significantly positive influence to the house price. These regression analyses not only confirmed that the adjustment of monetary policy along with the implications of the NEER indexes would have spillover effects on the house prices, but also showed the inconsistent results in different regions. The NEER indexes of fixed price level and 2% inflation would bring smaller positive impact, compared to the NEER indexes without price-stability consideration, to the house price of Beijing, Shanghai, and Shenzhen but stronger impact to Guangzhou and the national level. According to the empirical outcomes, the authorities should be very careful when conduct monetary policy because its discrepant spillover effect.