Abstract: The actual effect of reducing the social insurance fee rates is affected by various linked factors such as population, economy and other policies. Considering the impact of the central adjustment system on the capital flow of the pension fund, this paper constructs an actuarial model with the provinces as the research objects to simulate the operation of pension funds and the non-equilibrium of pension expenditures in the eight major economic regions in China, when the reformation of collection agencies, the reduction of rates, and the implementation of delayed retirement policies are simultaneously put into operation. The results show that, without other policy interventions, Heilongjiang, Hebei, Qinghai and other provinces will not have the financial feasibility of decreasing social insurance fee rates. There are greater differences in the pension sustainability among different regions, and this rate reduction policy in the southern coast areas has the longest duration. Without other policy interventions, if the collection rate increases by 10%, the reduction policy implemented nationwide will increase by 3.5 years. If the collection rate reaches 85%, and the delayed retirement policy is implemented simultaneously, the reduction policy can last for 12 to 25 years. Although delayed retirement can improve the sustainability of the fund, it should still choose the way of “small steps and slow walking”, otherwise, it will further widen the imbalance of fund expenditures among different regions.

Key words: social insurance fee rates, financial sustainability, region balance