Walk on the Wild Side: Temporarily Unstable Paths and Multiplicative Sunspots
提出一个允许暂时不稳定路径的理性预期框架，引入乘数太阳黑子冲击导致参数漂移和随机波动，并用计量方法估计模型。应用于1970年代美国通胀，发现暂时不稳定路径最能解释当时的滞胀。
We propose a generalization of the rational expectations framework to allow for temporarily unstable paths. Our approach introduces multiplicative sunspot shocks and it yields drifting parameters and stochastic volatility. Then, we provide an econometric strategy to estimate this generalized model on the data. The methodology allows the data to choose between different possible alternatives: determinacy, indeterminacy, and temporary instability. We apply our methodology to US inflation dynamics in the 1970s through the lens of a simple New Keynesian model. When temporarily unstable paths are allowed, the data unambiguously select them to explain the stagflation period in the 1970s.