中文摘要
就业稳定性的巨大差异是劳动力市场的一个关键特征,不稳定的职业生涯会导致养老金权益减少和生命周期财富积累降低。本文研究最优养老金制度应如何考虑就业稳定性的异质性。我构建了一个新颖的生命周期模型,该模型在摩擦性劳动力市场中刻画了异质性离职风险,并包含内生化的人力资本积累、消费—储蓄行为与退休决策。在对美国经济进行校准后,最优养老金制度的累进性显著高于现行社会保障制度,其最优给付方案接近一条给付下限。取消社会保障缴费上限会进一步提高累进性;这些改革合计为新进入劳动力市场者带来的福利收益相当于其终身消费的0.94%。尽管更高的累进性会扭曲人力资本投资并减少劳动供给,但保险收益占据主导。最优养老金制度为异质性职业风险提供了可观的保险保障,并降低了整个生命周期的消费不平等。
Abstract
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.