金融危機與貨幣政策-貨幣搜尋模型

Financial Crisis and Monetary Policy: Monetary Search Model

鍾孟蓉(Meng-Jung Chung)

指導教授 ： 林靜儀

國立清華大學/科技管理學院/經濟學系/碩士(2014年)

摘要

本文建構一個具有金融體系和投資市場的貨幣搜尋模型，來探討在何種情況中，央行會決定在原有的傳統貨幣政策基礎上再加進非傳統貨幣政策。Ferraris and Watanabe(2012)考慮投資市場的流動性，說明貨幣有助於緩解流動性短缺的問題，但並未考慮金融風暴衝擊與貨幣政策的影響。本文拓展其模型，考慮有金融風暴衝擊和非傳統貨幣政策的情況，證實出主要變數-利率、貨幣數量、通膨、投資、消費等的變動方向都會與Gertler and Karadi(2011)的DSGE模型之衝擊反應函數所帶出的主要變數變動方向一致。

本研究有以下三點發現: 一為利率是否有觸及ZLB，視銀行貸放意願決定之；當銀行貸放意願低到為零時，若央行沒有觀察到該現象，持續使用以利率調控為主的傳統貨幣政策，反而更會陷入ZLB問題。二為在傳統貨幣政策下，當利率為零時，由於銀行無法將央行注入貨幣轉成信用貸放出去，預持現金限制發生，消費財與投資財購買量將萎縮；在非傳統貨幣政策下，當利率為零時，由於可以跳脫銀行體系貸放意願的干擾，貨幣持有量增加，有效刺激消費與投資行為的成長。三為在低通膨環境，且銀行貸放意願為正時，傳統和非傳統貨幣政策對於經濟體的影響將更有效，貨幣數量的增加不僅大幅減少利率，也可以刺激消費和投資；高通膨環境，阻礙貨幣政策的成效，增加的貨幣數量會降低短期利率，但由於通膨過高，消費和投資有可能無法增加，反而還會萎縮，也就是長期利率可能不降反增，且非傳統貨幣政策由於無法立即退場，該政策造成的傷害將大於傳統貨幣政策。

關鍵字

信用 ； 流動性 ； 貨幣搜尋模型 ； 貨幣政策 ； 金融風暴

並列摘要

A model of investment market integrates financial intermediation theory with the monetary search framework. We use the model to explore in what circumstances that the central bank uses unconventional monetary policy rather than conventional monetary policy. Ferraris and Watanabe (2012) presents liquidity in investment market, and indicates the role of money to help ease liquidity shortage problems, but the article did not study the impact of the financial turmoil and monetary policy. Our article expands the model, considering the effect of the central bank using (un)conventional monetary policy to combat the financial crisis. We demonstrate that the direction of change of key variables - interest rate, the quantity of money, inflation, investment and consumption - is consistent with Gertler and Karadi (2011) of the DSGE model.

In this paper we address the following findings. First, whether interest rates have touched ZLB depends on the bank lending channel. When bank lending willingness is low to zero and the central bank did not observe this phenomenon to constant use conventional monetary policy, it is more likely to fall into ZLB problem. Second, when interest rates are close to zero in conventional monetary policy and the bank credit can’t be loaned out, the quantity of money decreases; and further, deflationary pressure will occur. When interest rates are close to zero in unconventional monetary policy and the policy excludes the impact of bank lending channel, the quantity of money effectively increases; and further, deflationary pressure can be lifted. Third, when bank lending willingness is positive in a low inflation environment, both conventional and unconventional monetary policies affect the economy more effectively and bring about the quantity of money to increase. In addition, its increase is not only significantly to reduce the short-term interest rate, but also stimulates consumption and investment. Monetary policies are not effective in a high inflation environment. Though the quantity of money reduces short-term interest rates, consumption and investment come to a recess as a result of a high inflation. Besides, unconventional monetary policy can’t exit immediately, so it causes even larger(greater) damage than conventional monetary policy.

並列關鍵字

Credit ； Liquidity ； Monetary Search Model ； Monetary Policy ； Financial Turmoil

參考文獻

6. 陳旭昇和湯茹茵 (2012)，「動態隨機一般均衡(DSGE)模型在貨幣政策制定上的應用: 一個帶有批判性的回顧與展望」，經濟論文叢刊，第40卷第3期，頁289-323。

10. 張德存和李映宣 (2013)，「流動性、資產與廠商投資決策」，經濟論文叢刊，第41卷第4期，頁477-506。

1. Acharya and Nagvi (2012), “The Seeds of a Crisis: A Theory of Bank Liquidity and Risk Taking Over the Business Cycle.” Journal of Financial Economics 106(2), 349-366.

2. Bernanke, Ben S. and Alan S. Blinder (1988), “Credit, Money, and Aggregate Demand,” American Economic Review 78, 435-439.

3. Bernanke, Ben S. and Mark Gertler (1995), “Inside the Black Box: The Credit Channel of Monetary Policy Transmission,” Journal of Economic Perspectives 9, 22-48.