Is There Chaos in The World Economy? A Nonparametric Test Using Consistent Standard Errors*
提出一种基于非参数Lyapunov指数估计量一致标准误的混沌检验方法，并对国际实际产出序列进行检验，发现许多情况下显著拒绝正Lyapunov指数的假设，暗示传统外生模型比混沌内生模型更能解释经济周期波动。
A positive Lyapunov exponent is one practical definition of chaos. We develop a formal test for chaos in a noisy system based on the consistent standard errors of the nonparametric Lyapunov exponent estimators. For international real output series, the hypothesis of the positive Lyapunov exponent is significantly rejected in many cases. One possible interpretation of this result is that the traditional exogenous models are better able to explain business cycle fluctuations than is the chaotic endogenous approach. However, our results are subject to a number of caveats.