This paper quantifies the welfare gains from Social Security when individuals face uninsurable longevity risk. While past researchers have studied this basic question, we do so from a unique perspective. In contrast to traditional macroeconomic models that abstract from specific linkages between parents and children, in our model, children are born to specific parents whose longevity is uncertain. And because parental asset holdings evolve over the life of the parent, children face uninsurable bequest income risk in addition to their own longevity risk. We find that Social Security improves ex ante expected utility by 3.4% of lifetime consumption (for the second generation). Because our baseline analysis assumes full information and optimal hedging of longevity risk, we treat these welfare gains as a conservative estimate, and we show that the gains are significantly larger when individuals fail to hedge their longevity risk.

本文量化了当个人面临无法投保的长寿风险时社会保障所带来的福利收益。虽然过去的研究人员已经研究过这个基本问题，但我们是从一个独特的角度来研究的。与从父母与孩子之间的特定联系中抽象出来的传统宏观经济模型相比，在我们的模型中，孩子是由特定父母所生的，他们的寿命不确定。而且由于父母的资产持有随着父母的一生而演变，除了他们自己的长寿风险外，孩子还面临着不可保险的遗产收入风险。我们发现，社会保障将事前预期效用提高了终生消费的 3.4%（对于第二代）。因为我们的基线分析假设完整的信息和长寿风险的最佳对冲，我们将这些福利收益视为保守估计，