The volatility trap: Precautionary saving, investment, and aggregate risk
研究永久性和暂时性收入冲击对预防性储蓄和投资的影响，发现永久冲击的高波动性导致高储蓄低投资，形成“波动性陷阱”，实证支持非线性关系。
Abstract We study the effects of permanent and temporary income shocks on precautionary saving and investment in a “store‐or‐sow” model of growth. High volatility of permanent shocks results in high precautionary saving in the safe asset and low investment or a “volatility trap,” namely, big savers invest relatively little. In contrast, low volatility of permanent shocks leads to low precautionary saving and high or low investment, depending on the volatility of temporary shocks. Empirical evidence shows a nonlinear relationship between investment and saving and that investment is a hump‐shaped function of the volatility of permanent shocks, as predicted by the model.