Credit and the Natural Rate of Interest
研究了借贷双方信息不对称和名义债务合同下自然利率的性质，发现标准定义的自然利率受货币政策影响，因此提出新定义，并分析了金融摩擦对自然利率动态和政策含义的影响。
We analyze the properties of the natural rate of interest in an economy with asymmetric information between borrowers and lenders, and nominal debt contracts. In our model, monetary policy has real effects in the flexible‐price equilibrium because it affects the cost of external finance. As a consequence, under the standard definition, the natural rate of interest is not a useful policy indicator because it is itself affected by monetary policy. We propose a generalized definition and demonstrate that the resulting natural rate (i) is not policy dependent and (ii) delivers price stability if used as the intercept of a monetary policy rule. From a qualitative perspective, the dynamics of the natural rate in response to shocks can be very different in economies with or without financial frictions. Quantitatively, the policy implications of these differences tend to be minor for real shocks, but sizable for financial shocks of the magnitude observed during the financial crisis of 2007–09.