Can learnability save new-Keynesian models?

• 成果类型: Article
• 署名作者: Cochrane, John H.
• 署名单位: University of Chicago; National Bureau of Economic Research
• 刊物名称: JOURNAL OF MONETARY ECONOMICS
• ISSN/ISSBN: 0304-3932
• DOI: 10.1016/j.jmoneco.2009.10.012
• 发表日期: 2009
• 页码: 1109-1113
• 关键词: New-Keynesian model; learning; learnability; multiple equilibria; indeterminacy

摘要

McCallum (2009) argues that learnability can save new-Keynesian models from indeterminacies. He claims the unique bounded equilibrium is learnable, and the explosive equilibria are not. However, he assumes that agents can directly observe the monetary policy shock. Reversing this assumption, I find the opposite: the bounded equilibrium is not learnable and the unbounded equilibria are learnable. More generally, I argue that a threat by the Fed to move to an unlearnable equilibrium for all but one value of inflation is a poor foundation for choosing the bounded equilibrium of a new-Keynesian model. (C) 2009 Elsevier B.V. All rights reserved.