Abstract: In order to improve the sustainability of Urban Employees’Pension System，some schol- ars suggest that it’s useful to improve the financial situation of pension fund effectively by adjusting the contributory service policy ( e． g．by increasing the minimum vesting period or mandatory retirement age) ．Based on the system，this paper builds the actuarial model from pay-as-you-go and funded fi- nance perspective，to analyze the effect of the contribution service policy adjusting on the sustainability of the system through the “contribution period”variable．The result shows that，average employee should contribute for more than 20 years to keep the horizontal balance of the pension fund under the frame of the current system．Moreover，it’s difficult to improve the financial situation of pension fund ef- fectively even if we lengthen the minimum vesting period or raise the mandatory retirement age．The conclusion shows that State Council Document 38 in 2015 decreases the effect of increasing the contribu- tory period on the system sustainability．Therefore，the expected effect of increasing the mandatory re- tirement age should be re-examined．The paper suggests that we should insist the principle of actuarial balance and take comprehensive measures to build a fair and sustainable system．

Keywords:  Urban Employees’Pension System, Contributory Service, Expected Future Lifetime at Retirement, Treatment-contribution Ratio

摘要： 为增强职工基本养老保险制度可持续性,有学者提出,通过调整缴费年限政策,包括提高最低缴费年限和延迟退休等,以改善基金状况。文章基于现行制度设计,运用精算技术,分别构建了代际赡养和同代自养的缴费年限测算模型,通过"缴费年限"这一核心变量,评估了缴费年限政策调整对基金平衡的影响。结果发现:现行制度下,要维持基金横向平衡,参保人员平均缴费年限不得低于20年,且提高最低缴费年限或者延迟退休,难以有效改善基金状况。研究结果表明,国发〔2005〕38号文的规定减轻了"增加缴费年限改善基金状况"的效果,因而关于延迟退休等举措的预期效果需重新审视,建议按照长期精算平衡的原则,通过综合施策,形成更加公平和更可持续的制度。 

关键词: 职工基本养老保险,  缴费年限,  退休余命, 待遇缴费比