Collaborative Research: Experimental Evidence on Monetary Policies

2008-09年的大衰退导致央行尝试非传统的货币政策，例如日本、英国和美国的量化宽松政策。以及丹麦、瑞典和欧元区超额准备金的负利率。然而，由于必须在可预见的范围内避免这些非传统政策对宏观经济的有害影响，政策试验的程度大大降低。在这个项目中，我们制定了一个议程，在实验室的受控条件下更广泛地进行货币政策实验，目的是在该领域实施各种货币政策之前了解其福利后果。 我们的方法类似于在飞机允许飞行之前对飞机进行风洞测试。在小规模、低风险的实验室环境中，对货币政策的研究与有偿的人类受试者相比，限制要少得多，成本也要低得多，因此可以评估一套更丰富甚至激进的货币政策。 事实上，我们的目标是提供新的证据，各种货币政策的福利影响，这将是困难的，如果不是不可能在该领域实施，至少没有一些关于其有效性的先前证据。 我们寻求开始收集此类证据的进程。 更大的目标是，在评价不同货币政策的效果时，货币政策的实验室测试可以作为理论和实地数据的实证分析的补充工具。货币政策分析的框架是我们以前在实验室实施的货币经济学中的主力模型--拉各斯和赖特的货币搜索理论模型。 在这个项目中，我们建议使用拉各斯-赖特模型来探讨著名的弗里德曼规则（弗里德曼1969）的货币政策。 众所周知，弗里德曼规则在各种不同的货币模型中都是最优的，包括拉各斯-赖特模型。 从本质上讲，弗里德曼表明，福利最大化的货币政策是设定通货膨胀，以使名义利率-持有货币的私人边际成本-等于零。 由于生产更多货币的社会边际成本基本上为零，如果私人边际成本为正，就会出现一个无效缺口，而这个缺口可以通过使名义利率等于零来弥补。由此可见，如果安全政府债券的真实的收益率为？0，而名义利率i由费雪方程给出，为i= EI + Ei，其中EI表示预期通胀率，那么，为了使i=0，中央银行应该努力使EI = -Ei = 0。尽管中央银行家们无疑意识到弗里德曼规则，并且经常表达对低通胀的真正愿望，但中央银行家们主张，更不用说试图实施弗里德曼规则通常要求的负通胀率（通缩），这将是非常违背传统智慧的。 在实验室中，我们不受这些考虑的约束，因此我们建议以两种不同的方式实施弗里德曼规则，并评估福利影响。 第一种方法是上述类型的通货紧缩货币政策。第二种方法是为持有的货币支付具有竞争力的市场利率，从而完全消除持有货币的私人边际成本。 与第一种方法一样，对手头现金提供利息的实际性可能使这种可能性不可行。在这个项目中，我们将首次探索弗里德曼规则在我们实验性的拉各斯-赖特经济中的两种实现方式。 除了探索弗里德曼规则的两种不同实施方式的福利后果之外，我们还对使用我们的框架来研究通货膨胀政策的福利后果感兴趣。具体来说，我们感兴趣的是低通胀率与高通胀率的福利成本，我们建议通过改变货币增长率来解决这个问题。 最后，在我们之前的一项研究的基础上，我们希望研究对使用法定货币（例如纳税）的法律的限制是否对采用法定货币和福利有影响。

The Great Recession of 2008-09 led central banks to experiment with non-traditional monetary policies, for example, quantitative easing in Japan, the U.K. and the U.S. and negative interest rates on excess reserves in Denmark, Sweden and the Eurozone. Nevertheless, the extent of policy experimentation was greatly tempered by the need to avoid, to the extent foreseeable, harmful macroeconomic impacts from these non-traditional policies. In this project we set out an agenda for conducting monetary policy experiments more broadly in the controlled conditions of the experimental laboratory with the aim of understanding the welfare consequences of various monetary policies prior to their possible implementation in the field. Our approach is analogous to wind-tunnel testing of aircraft before the aircraft is allowed to fly. The study of monetary policies in the necessarily small-scale, low-stakes laboratory environment with paid human subjects is much less restrictive or expensive than experimentation in the field, thereby allowing for evaluation of a much richer and even radical set of monetary policies. Indeed, our aim is to provide new evidence on the welfare impacts of various monetary policies that would be difficult, if not impossible to implement in the field at least without some prior evidence on their effectiveness. We seek to begin the process of gathering such evidence. Our larger goal is to demonstrate that laboratory tests of monetary policies can be a complementary tool to theory and empirical analysis of field data in the evaluation of the efficacy of different monetary policies.Our framework for monetary policy analysis is Lagos and Wright's search-theoretic model of money, a work-horse model in monetary economics that we have previously implemented in the laboratory. In this project we propose to use the Lagos-Wright model to explore the celebrated Friedman rule (Friedman 1969) for monetary policy. The Friedman rule is known to be optimal in a very wide variety of different monetary models, including the Lagos-Wright model. In essence, Friedman showed that the welfare-maximizing monetary policy is to set inflation so as to make the nominal interest rate - the private marginal cost of holding money -- equal to zero. Since the social marginal cost of producing more money is essentially zero, if the private marginal cost were positive, there would be an inefficient gap that could be closed by making the nominal interest rate equal to zero. It follows that, if the real rate of return on safe government bonds is ñ0, and the nominal interest rate, i, as given by the Fisher equation, is i= EI + ñ, where EI denotes the expected inflation rate, then, in order for i=0 the central bank should work to set EI = -ñ 0. While central bankers are undoubtedly aware of the Friedman rule and often express a genuine desire for low inflation, it would be very much against conventional wisdom for central bankers to argue for, let alone attempt to implement, a negative inflation rate (deflation) as the Friedman rule would typically require. In the laboratory we are not bound by such considerations and thus we propose to implement the Friedman rule in two different ways and assess the welfare implications. The first approach is a deflationary monetary policy of the type outlined above. The second approach is to pay a competitive market interest rate on money holdings removing altogether the private marginal cost from holding money. As with the first approach, the practicalities of providing interest on hand-to-hand cash holdings has likely rendered this possibility unworkable. In this project we explore, for the first time both implementations of the Friedman rule in our experimental Lagos-Wright economy. In addition to exploring the welfare consequences of the two different implementations of the Friedman rule, we are also interested in using our framework to study the welfare consequences of inflationary policies. Specifically, we are interested in the welfare costs of low versus high inflation rates, and we propose to address this question by varying the money growth rate. Finally, following up on one of our previous studies, we wish to study whether legal restrictions on the use of fiat money (e.g. to pay taxes) matter for the adoption of fiat money and for welfare.