We analyze the role of pay-as-you-go social security in intragenerational risk sharing in an overlapping-generations model with individual heterogeneity. Parents invest in their children’s education in state schools in exchange for old-age financial support. Due to random factors such as luck in the job market, children may have different earning capacities despite that they receive the same education. Without social security, a parent gets a transfer payment from her own child, so the received amount is uncertain as it depends on the child’s earnings. The social security scheme, which essentially serves to pool transfer contributions from all children and then redistribute them equally to each parent, insures parents against the risk of educational investments. Our model shows that social security stimulates educational spending, enhances labor earnings, and increases ex ante individual utility. However, it may worsen ex post intragenerational inequality of lifetime income.

在具有个体异质性的重叠世代模型中，我们分析了现收现付的社会保障在世代内风险分担中的作用。父母在公立学校投资于子女的教育，以换取养老金。由于就业市场中的运气等随机因素，尽管孩子接受相同的教育，他们的收入能力可能会有所不同。没有社会保障，父母将从自己的孩子那里获得转移支付，因此，所接收的金额不确定，这取决于孩子的收入。社会保障计划实质上是汇集所有孩子的转移缴款，然后将其平均分配给每位父母，从而确保父母免受教育投资的风险。我们的模型表明，社会保障可以刺激教育支出，事前个人效用。但是，它可能恶化事后终生收入的代内差距。