缴费年限对养老保险基金支付风险的影响研究

A Study on the Impact of Contribution Years on the Payment Risk of Social Pension Insurance Fund

缴费年限直接影响着养老保险基金的缴费积累与参保者的待遇水平。能够领取养老金的缴费年限由最低缴费年限和退休年龄框定,参保者在缴费年限上具有较大的自主选择权。本文根据城镇职工基本养老保险现行制度设计,运用保险精算方法,构建了基金支付风险精算模型,并依据该模型实证评估了缴费年限对养老保险基金支付风险的影响。研究结果表明:单方面提高最低缴费年限并不能降低基金支付风险,根本原因在于“长缴多得”的计发机制;退休年龄的延长确能降低基金的支付风险,“早缴费”、“长缴费”将是减少养老基金支付风险的重要举措,但需要辅之以最低缴费年限调整才能充分发挥延迟退休增收减支作用;同一退休年龄下,女性比男性获益程度更高,相应地对实现缴费与待遇平衡产生更大的负效应;缴费年限增加能够提高替代率,增强制度的保障功能;缴费比例降低以及退休后平均余命、城镇单位就业人员平均工资增长率、养老金增长率、个人账户记账利率以及平均缴费工资指数提高会增大基金支付风险。建议通过调整退休年龄辅之以最低缴费年限并进行参量调整以降低基金支付风险。

Contribution years directly affect the accumulation of pension funds and the benefit level of the participant. The contribution years are decided by the minimum contribution years and retirement age, therefore the participant has a great discretion on the contribution years. Based on the current system design of basic social pension insurance for urban workers, this paper constructed an actuarial model of pension fund payment risk, and empirically evaluated the impact of contribution years on the fund payment risks. The results show that unilaterally increasing the minimum contribution years cannot reduce the pension fund payment risk, and the fundamental reason lies in the " longer contribution higher benefit" mechanism. The extension of retirement age can indeed reduce the payment risk, and " early contribution" and " longer contribution" are important measures to reduce the payment risk, but it needs to be supplemented by the adjustment of minimum contribution years to give full play to its function of increasing fund balance and reducing payout. Under the same retirement age, women benefit more than men, which has a greater negative effect on achieving the balance of contribution and benefits. The increase in the contribution years can improve the replacement rate and enhance the protection function of the system. The reduction of contribution ratio and the increase in life expectancy after retirement, average wage growth rate of urban employees, pension growth rate, individual account crediting rate and average contribution wage index will increase the risk of fund payment. It is suggested that the risk of fund payment should be reduced by adjusting the retirement age, supplemented by requirement of minimum contribution years and parameter adjustment.