人口结构与经常账户:开放DSGE模拟与经验证据

Demographic Structure and Current Account:Open DSGE Simulation and Empirical Evidence

本文在动态随机一般均衡模型中引入人口年龄结构,分析其对经常账户的效应,并用全球数据进行经验分析。我们细分了3种年龄类型的经济体后发现,人口结构冲击总体表现为中年、老年人口比重负向影响经常账户余额。本文还构建不包含短期冲击的动态一般均衡模型,发现人口结构长期趋势与短期冲击对经常账户的影响基本相同。全球181个经济体1960-2015年数据验证了上述理论发现。政策模拟显示选择退休年龄政策时宜考虑当时不同的年龄结构。当中年人口占比较高时,从外部经济均衡的角度出发,延长退休年龄宜小步推进;但当老龄人口比例已经较大时,延迟退休年龄则可缓解经常账户余额下行压力。

In this paper,we build an open DSGE model to study the effects of demographic structure on current account.When we break the economic model down into the three age-groups,we find that the proportion of young people positively affects the current account balance in the long term,while variation in the middle and elderly aged groups presents a negative impact.We then use data from 181 economies between 1960 and 2015 to test these theoretical findings.The empirical results show that there is a significantly negative correlation between the fraction of the population aged 15 or over and the current account,while this is positive for the cohort aged between 0 to 14,which corresponds to most simulated population environments in the DSGE model and is also coherent with our empirical analysis.We also carry out four counterfactual policy experiments related to the retirement age in China.The results of the simulation show that when the proportion of middle-aged population is still high,from the perspective of the external economic equilibrium,it is better to gradually increase the retirement age.However,when the proportion of the elderly population is already large,postponement of retirement age can alleviate downward pressure on current account balances.