Money, Interest, and the Channels of Monetary Transmission

货币政策对经济产生影响的渠道有多多样？货币政策的总体立场是否可以简单地通过考察短期名义利率的行为来概括？或者货币存量的变化也很重要吗？这些问题--在本研究项目中要解决的问题--不仅对流行的宏观经济模型的规范有影响，而且对美国宏观经济政策在不久的将来可能必须实施的方式也有影响。 解决这些问题的出发点是货币传导机制的基准模型，其变体出现在最近关于货币政策及其对经济影响的文献中。这个基准模型假设货币政策对产出的影响完全来自于政策对短期名义利率的影响。货币存量的变化对产出行为有影响，但只有在货币存量的变化首先影响利率的情况下才有影响。该项目考虑了对这一基准模型的两组修改，这两组修改都意味着货币存量的变化在传导机制中发挥更重要、更直接的作用。第一个修改通过代表性家庭效用函数中的不可分离性引入了货币的直接影响。第二个也是更广泛的修改允许货币以基准模型所不具备的方式成为私营部门财富的一个组成部分。在第二个修正模型中，出现了庇古的真实的平衡效应，即使在名义利率达到零下限后，货币政策也可以影响经济。 这个研究项目的一个显著特点是，考虑的每个模型将估计与正式的计量经济学技术;统计假设检验将被用来区分货币传导机制的竞争观点。

How diverse are the channels through which monetary policy actions impact on the economy? Can the overall stance of monetary policy be summarized simply by examining the behavior of the short-term nominal interest rate? Or do changes in the money stock matter as well? These questions--the ones to be addressed in this research project--have implications, not just for the specification of popular macroeconomic models, but also for the way in which US macroeconomic policy may have to be conducted in the not-too-distant future. The starting point for addressing these questions is a benchmark model of the monetary transmission mechanism, variants of which appear throughout the recent literature on monetary policy and its effects on the economy. This benchmark model assumes that the impact of monetary policy on output comes exclusively through the effects that policy has on the short-term nominal interest rate. Changes in the money stock can matter for the behavior of output, but only to the extent that those changes in money affect the interest rate first. The project considers two sets of modifications to this benchmark model, both of which imply that changes in the money stock play a more important, direct role in the transmission mechanism. The first modifications introduce direct effects of money through nonseparabilities in a representative household's utility function. The second--and more extensive--modifications permit money to become a component of private-sector wealth in a way that the benchmark model does not. In this second modified model, a Pigouvian real balance effect arises, allowing monetary policy to influence the economy even after the nominal interest rate hits its zero lower bound. A distinguishing feature of this research project is that each of the models considered will be estimated with formal econometric techniques; statistical hypothesis tests will then be used to discriminate between competing views of the monetary transmission mechanism.