I study the role of social security in providing insurance when there is adverse selection in the annuity market. I calculate welfare gain from mandatory annuitization in the social security system relative to a laissez-faire benchmark, using a model in which individuals have private information about their mortality. I estimate large heterogeneity in mortality using the Health and Retirement Study. Despite that, I find small welfare gain from mandatory annuitization. Social security has a large effect on annuity prices because it crowds out demand by high-mortality individuals. Welfare gain would have been significantly larger in the absence of this effect.

We study Pareto optimal policy reforms aimed at overhauling retirement financing as an integral part of the tax and transfer system. Our framework for policy analysis is a heterogeneous‐agent overlapping‐generations model that performs well in matching the aggregate and distributional features of the U.S. economy. We present a test of Pareto optimality that identifies the main source of inefficiency in the status quo policies. Our test suggests that lack of asset subsidies late in life is the main source of inefficiency when annuity markets are incomplete. We solve for Pareto optimal policy reforms and show that progressive asset subsidies provide a powerful tool for Pareto optimal reforms. On the other hand, earnings tax reforms do not always yield efficiency gains. We implement our Pareto optimal policy reform in an economy that features demographic change. The reform reduces the present discounted value of net resources consumed by each generation by about 7 to 11 percent in the steady state. These gains amount to a one‐time lump‐sum transfer to the initial generation equal to 10.5 percent of GDP.

Using a dynamic panel approach, we provide empirical evidence that negative health shocks significantly reduce earnings. The effect is primarily driven by the participation margin and is concentrated among the less educated and those in poor health. Next, we develop a life-cycle model of labour supply featuring risky and heterogeneous frailty profiles that affect individuals’ productivity, likelihood of access to social insurance, disutility from work, mortality, and medical expenses. Individuals can either work or not work and apply for social security disability insurance (SSDI/SSI). Eliminating health inequality in our model reduces the variance of log lifetime (accumulated) earnings by 28% at age 55. About 60% of this effect is due to the impact of poor health on the probability of obtaining SSDI/SSI benefits. Despite this, we show that eliminating the SSDI/SSI program reduces ex ante welfare.