摘要
本文通过世代交叠模型,分析了我国人口结构沿着“数量-质量”前沿边界转换,即少子化伴随人力资本进步时,养老金体系最优的代际再分配水平。分析表明:(1)如果仅面临少子化,我国养老金体系的确应转向积累制,但快速的人力资本进步完全可以补偿少子化的冲击,使现收现付制仍是最优选择。如果考虑到代际公平性,甚至政府需要加强现收现付制,使老年世代分享经济发展的成果。(2)基于“数量-质量”前沿边界转换的模型内生出我国较高的养老保险费率、退休前工资替代率和制度内赡养率,较低的社会平均工资替代率和人口赡养率等许多令人困惑的典型事实。(3)在此理论框架下,无论不做实个人账户,还是加强缴费受益关联、延迟退休以及建立“养老金-工资挂钩机制”都有利于增进社会福利。看似矛盾的中国养老金改革实践或许具有逻辑自洽性。
To deal with its aging population,China started systemic pension reform through transferring from PAYGO to the partial fund program in the 1990s.However,in practice,the reform seems to be“looking right but going left.”The“funded individual accounts”emphasized in policy are operated as“non-financial accounts”in reality.The pension fund is meant to continuously improve the pension benefits of the elderly.In terms of redistribution,on the one hand,the government has strengthened the intergenerational transfer payment through the PAYGO system;on the other hand,it has weakened the intragenerational transfer payment and enhanced the connection between pension benefits and contributions.Strengthening the connection between benefits and contributions is intended to curb moral hazard.Conversely,improving the overall level of benefits might lead to early retirement and serious moral hazard problems.What are the social welfare outcomes of these seemingly contradictory reforms?Logically speaking,can these reforms be self-consistent?It is worth noting that China's low fertility and aging population are accompanied by rapid intergenerational human capital progress.Therefore,whether the continuous improvement in population quality can make up for the shortage in population quantity,and whether the PAYGO system remains the optimal policy are questions to be answered.We use an overlapping generation model to assume that the economy moves along a frontier of a population quantity-quality tradeoff,which assumes that the fertility rate decreases and human capital increases.The research results show that when the rapid progress of human capital can fully compensate for the impact of the low fertility rate,the PAYGO system is the best choice.This finding can explain some of the characteristics of“looking right but going left”in China's pension reform.The model,in incorporating intergenerational fairness,shows that in the rapid progress of human capital,the government should increase the degree of intergenerational transfer so that the elderly can share the achievements of economic development.This concern about intergenerational fairness might explain why the government uses funds to improve the overall pension benefit level rather than to finance personal accounts.However,a high contribution rate and high replacement rate might lead to moral hazard problems such as early retirement,restricting the term of the government's intergenerational transfer payment.To control moral hazard and expand the term of intergenerational transfer payment,it is necessary for the government to delay the statutory retirement age and strengthen the relationship between pension benefits and contributions.This way,the Chinese government might enhance intergenerational redistribution and weaken intragenerational redistribution.By the calibration and numerical simulation,we find that the model based on the population quantity-quality frontier movement can endogenously generate many of the stylized facts given by Fang&Zhang(2018).Moreover,in this theoretical model,the government's various policies—including adopting non-financial accounts,strengthening the connection between benefits and contributions,delaying the statutory retirement age,and linking the growth rate between pension and wage—improve social welfare.Thus,the seemingly contradictory practices of China's pension reform have logical self-consistency given the progress of human capital and concerns about intergenerational fairness.Following Song et al.(2015)and Fang&Zhang(2018),this study further explains the overall logic and social welfare outcomes of China's pension reform,and provides a new theoretical perspective through which to rethink its rationale.Previous studies may exaggerate the government's failure and neglect to examine the productivity factors that affect China's pension system.We find that a model based on the movement along the population quantity-quality frontier can better explain the stylized facts and the reform's path selection.An aging population might be caused by lower fertility rates or longer life expectancy.Although this study focuses on lower fertility rate,the conclusions are applicable to an aging population that has emerged due to prolonged life expectancy.
作者
张熠
张书博
汪润泉
ZHANG Yi;ZHANG Shubo;WANG Runquan(School of Public Economics and Administration,Shanghai University of Finance and Economics;School of Public Administration,Nanjing University of Finance and Economics)
出处
《经济研究》
CSSCI
北大核心
2020年第8期188-205,共18页
Economic Research Journal
基金
国家自然科学基金项目(71503154)资助。
关键词
人力资本
少子化
现收现付制
代际公平
养老金改革
Human Capital
Low Fertility
Pay-As-You-Go
Intergenerational Fairness
Pension Reform
