Does the New Keynesian Model Have a Uniqueness Problem?
Does the New Keynesian Model Have a Uniqueness Problem?
复制标题
新凯恩斯主义模型是否存在唯一性问题？
DOI：
10.3386/w24612
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
B. Johannsen
中科院分区：
文献类型：
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作者：
Lawrence J. Christiano;M. Eichenbaum;B. Johannsen
本文讨论了在零下限（ZLB）条件下，新凯恩斯（NK）模型的财政政策分析中，均衡的非唯一性是否是一个实质性问题。如果没有令人信服的方法在对关键政策问题给出不同答案的不同均衡中进行选择，就会出现实质性问题。我们认为，可学习性提供了这样一个标准。本文研究了一个具有Calvo定价摩擦的完全非线性NK模型。我们的主要发现是，我们分析的模型在ZLB有一个唯一的E-稳定的理性预期均衡。该均衡在学习下也是稳定的，并继承了财政政策线性NK模型的所有关键属性。
This paper addresses whether non-uniqueness of equilibrium is a substantive problem for the analysis of fiscal policy in New-Keynesian (NK) models at the zero lower bound (ZLB). There would be a substantive problem if there were no compelling way to select among different equilibria that give different answers to critical policy questions. We argue that learnability provides such a criterion. We study a fully non-linear NK model with Calvo pricing frictions. Our main finding is that the model we analyze has a unique E-stable rational expectations equilibrium at the ZLB. That equilibrium is also stable-under-learning and inherits all of the key properties of linearized NK models for fiscal policy.