活在当下还是着眼未来:中国跨期替代弹性的估计与决定

Today or Tomorrow:Estimation of China’s Elasticity of Intertemporal Substitution

消费跨期决策体现了经济主体对现在消费和未来消费的权衡,通常用跨期替代弹性衡量。本文运用中国家庭追踪调查、中国健康与养老追踪调查以及中国家庭金融调查3个微观数据库,估计了4种效用函数形式下中国的跨期替代弹性。结果显示,样本期中国跨期替代弹性均值为0.1526,取值区间分别为[0.1304,0.1694]、[0.1349,0.1558]、[0.1485,0.1767]。这意味着相对当前边际效用,如果未来消费边际效用上升100%,中国家庭将更偏好未来消费,消费总增长率将平均上升15.26个百分点。我们还发现,越富有、年龄越长、身体越差的群体越倾向于未来消费,跨期替代弹性越高。在理论意义上,本文细致估计了跨期替代弹性,为后续研究提供设定参考。在现实意义上,随着中国人口学特征的快速改变,家庭将更着眼未来,政策上需提前应对。

The elasticity of intertemporal substitution(EIS)is generally used to measure the dissociative intertemporal changes in consumption by economic entities over time,which affects asset allocation through household intertemporal consumption decision-making.This paper estimates the EIS based on four utility functions using survey data from three large micro-databases:the China Family Panel Studies(CFPS),the China Health and Retirement Longitudinal Study(CHARLS),and the China Household Finance Survey(CHFS).The results show robustness in the EIS estimates for different utility functions with an average value of 0.1526.The range of the values varies between 0.1304 and 0.1694 for CFPS,0.1349 and 0.1558 for CHARLS,and 0.1485 and 0.1767 for CHFS datasets.This suggests that when the future consumption marginal utility increases with respect to the current one,families prefer future consumption.When the ratio of the future consumption marginal utility to that of the current period doubles,the corresponding gross consumption growth rate increases by an average value of 15.26%.The study also reveals that EIS increases with wealth and age and decreases with health status.From a theoretical perspective,the paper estimates the EIS parameter in detail,providing a reference environment for follow-up studies.From a practical perspective,with the rapid changes in China’s demographic characteristics,this suggests that families are more focused on the future and therefore policies need to be addressed in advance.