最优累进养老金制度与异质性劳动力市场风险

摘要

Large differences in employment stability are a key feature of the labor market, with unstable careers leading to reduced pension entitlements and lower life-cycle wealth accumulation. This paper studies how optimal pension systems should account for heterogeneity in employment stability. I develop a novel life-cycle model that features heterogeneous job-separation risk with endogenous human capital accumulation, consumption-saving behavior, and retirement decisions in a frictional labor market. Calibrated to the U.S. economy, the optimal pension system is substantially more progressive than the current Social Security system, with an optimal benefit schedule that approaches a benefit floor. Abolishing the Social Security cap further increases progressivity; together, these reforms generate welfare gains equivalent to 0.94% of lifetime consumption for new labor market entrants. Although higher progressivity distorts human capital investment and reduces labor supply, the insurance gains dominate. The optimal pension system provides substantial insurance against heterogeneous career risk and reduces consumption inequality over the life cycle.