关键词: 现收现付制, 基金制, 养老金缴费率, 社会福利, OLG模型

Abstract:  Theoretical studies generally show that as a financing pattern of endowment insurance, the funded system is superior to the payasyougo system from the perspective of capital per capita. This article analyzes whether the funded system is completely superior to the payasyougo system from the perspective of welfare economics with exogenous and endogenous fertilities. The theoretical model shows that: under a certain combination of parameters, either with exogenous fertility or endogenous fertility, there exists a contribution rate of pension that the social welfare under payasyougo system is higher than that under funded system. The numerical simulation shows that: the contribution rate of pension can make the social welfare under the payasyougo system higher. And in the case of exogenous fertility (which is in line with Chinas fertility policy), the social welfare is the highest when the contribution rate of payasyougo pension is around 12%; in the case of endogenous fertility (which is in line with developed countries fertility policy), the social welfare is the highest when the contribution rate of payasyougo pension is around 6%. The former value is similar to the existing research conclusions that Chinas contribution rate of payasyougo pension should be reduced to around 15%, and the latter value is similar to the current contribution rate of payasyougo pension in developed countries such as the United States (6.2%) and Japan (7.7%). The robustness test shows that: the conclusions of the numerical simulation remain as long as the parameter assignment is within a reasonable range. This paper provides theoretical support for the reduction of Chinas contribution rate of payasyougo pension.

Key words: payasyougo system, funded system, contribution rate of pension, social welfare, OLG model