流动性陷阱之谜的解析

Analysis on the Puzzle of Liquility Trap

流动性陷阱的概念源于凯恩斯。凯恩斯、希克斯和克鲁格曼都认为,流动性陷阱是在利率很低的情况下由现金或货币对债券的完全替代造成的。但日本的实际经历表明,在陷入流动性陷阱的情况下,现金或货币对债券的替代是很不充分的。实际上,利率是由可贷资金的需求和供给决定的,而不是由货币的需求和供给决定的,货币流通速度是易变的而不是相对稳定的。流动性陷阱是在经济衰退和利率很低的情况下,货币供给转变为可贷资金供给的途径遇到障碍,货币流通速度下降抵消了货币供给增加的影响从而造成的。然而,克鲁格曼围绕流动性陷阱所提出的关于国际商品和资本流动问题、金融机构的反应问题、财政政策作用的问题、中央银行的可信度问题的分析基本上是正确的。

The concept of Liquility Trap came from John M. Keynes’ s thought. John M. Keynes, John Hicks and Paul R. Krugman believed that Liquility Trap would happen in following situation: bonds were replaced fully by money when interest rate was very low. However, according to real experience of Japan, bonds were not replaced fully by money when interest rate was very low. Acturally, interest rate is determined by demand and supply of loanable funds. It is not determined by demand and supply of money. Velocity of money circulation is volatile. It is not stable. Liquility Trap means low intreast rate and economic recession. Under this circumstance, monetary supply is difficult to change into loanable funds, and decrease of velocity of money circulation offsets the increase of monetary supply. But Paul R. Krugman’s analysis is almost correct about following question: cross border flow of commodities and capitals, reaction of financial institutions, the role of fiscal policy and credit of central bank.