Optimal Annuitization with Stochastic Mortality and Correlated Medical Costs
在Yaari框架中引入随机死亡率，发现医疗成本与年金剩余现值相关会降低年金需求，多数家庭不应持有正年金，甚至应持有负年金。
The conventional wisdom since Yaari (1965) is that households without a bequest motive should fully annuitize their investments. Numerous frictions do not break this sharp result. We modify the Yaari framework by allowing a household's mortality risk itself to be stochastic due to health shocks. A lifetime annuity still helps to hedge longevity risk. But the annuity's remaining present value is correlated with medical costs, such as those for nursing home care, thereby reducing annuity demand, even without ad-hoc liquidity constraints. We find that most households should not hold a positive level of annuities, and many should hold negative amounts.