中文摘要：

养老金研究的核心问题之一在于选择合适的养老金计划运行方式。文章基于中国实际，通过引入随机性的“权衡理论”模型分析发现，在代表性参保人效用最大化前提下，运行方式选择类似于金融资产组合问题。所谓的艾隆条件只是在确定性模型下的特定结果。在加入风险因素后，即便在艾隆条件下，引入一定的积累制也将改善养老金体系的运行状况。两种制度最优的混合比例将受到人口增长率、工资增长率、个人风险规避倾向和金融市场因素的共同影响。分析结果表明提高养老金计划运行收益率和养老基金分散化投资有利于增进参保人效用。

英文摘要：

One of the most important issues on pension research is how to choose the optimal pension plan. Based on the real background in China, this paper introduces a stochastic trade-off model and shows that the choice of operation mode of public pension plan is similar to the portfolio of finan- cial assets under the representative insured person＇s utility maximization. The so-called Aaron condition is just a specific case in deterministic models. After considering risk factors, the introduction of fully funded system would improve the operation of public pension system even under Aron condition. The optimal mixed proportion of pay-as-you-go system and fully funded sys- tem is affected by population growth rate, wage growth rate, individual risk aversion and financial market factors. The results indicate that the increase in operation efficiency of public pension plan and diversified investment of pen- sion funds are beneficial to the improvement of the utility of insured persons.