《保险研究》20240207-《基于参保者收入异质性的养老金结构优化问题研究》（王论意、何林）

［摘   要］为了应对人口老龄化对现收现付制养老保险的冲击，我国大力发展个人养老金制度。其中，税收优惠政策是提升个人养老金回报效率、实现个人养老金制度扩面的重要保障。不同收入群体适用的税率不同，参与个人养老金制度所享受的税收优惠幅度存在差异，从而产生异质化的养老金回报效率和偏好顺序。本文将参保人的收入异质性纳入理论模型，建立起不同收入参保群体与政府决策的Stackelberg 均衡，求得PAYGO养老金、个税递延EET养老金和个人储蓄的最优配比。在基准模型中，高收入群体倾向于顶格缴纳EET养老金税延额度，中等收入和低收入群体则选择部分缴纳EET养老金税延额度；最优PAYGO缴费率和最优EET缴费限额比当前的缴费制度具有更好的校准效果。研究还发现：扩大中等收入群体规模，有助于增大社会总福利；提高EET的投资回报率有助于实现个人养老金制度扩面；个人养老金制度的税收优惠措施可考虑从“提高缴费限额”和“降低领取税率”两个方面着手，在不增大政府财政负担的前提下，优化税收优惠效果。

［关键词］收入异质性；税收优惠；个人养老金；Stackelberg均衡；财政效用

［基金项目］本文由国家社会科学基金重点项目“构建金融有效支持实体经济着力点的体制机制研究”（21AZD028）支持。

［作者简介］王论意，中国人民大学财政金融学院博士研究生，研究方向：最优保险设计、个人养老金；何林（通讯作者），中国人民大学财政金融学院教授、博士生导师，研究方向：个人账户养老金投资管理、社会养老保险精算建模。

A Research on the Optimization of Pension Structure Based on Income Heterogeneity among Policyholders

WANG Lun-yi,HE Lin

Abstract：To address the challenges posed by an aging population on the existing pay-as-you-go (PAYGO) pension system,China has actively promoted individual pension schemes.The tax incentive policy has been instrumental in optimizing individual pension returns and broadening its coverage.Diverse tax rates applicable to different income groups determine the level of tax benefits individuals receive when participating in individual pension plans,leading to varied preferences and pension return efficiencies.This paper incorporates income heterogeneity among policyholders into a theoretical model,establishing Stackelberg equilibriums between distinct income groups and the government.Within this framework,we calculate optimal contribution ratios for the PAYGO pension,EET pension,and individual savings.In the benchmark model,high-income groups are inclined to maximize contributions to the EET pension,while middle and low-income groups opt for partial contributions.Additionally,results for the optimal PAYGO contribution rate and EET contribution limit exhibit a better-calibrated effect compared to current pension practices.The study highlights that expanding the middle-income group contributes to overall social welfare.Increasing the return rate facilitates the expansion of individual pension coverage.Furthermore,optimizing tax incentives for individual pensions involves both “raising the contribution limit” and “lowering the tax rate receiving the benefit.” These adjustments can be implemented without escalating the government′s fiscal burden,thereby enhancing the efficiency of tax incentive policies.

Key words：income heterogeneity;tax incentives;individual pensions;Stackelberg Equilibrium;fiscal utility