Annuities and Individual Welfare
放宽了完全年金化的最优条件，发现市场不完全时部分年金化仍最优，但完全年金化不成立；未保险医疗支出对年金需求的影响取决于风险时机，且即使消费路径与年金收入差异大，人们仍偏好大量年金化，暗示有限购买可能源于心理偏差。
Advancing annuity demand theory, we present sufficient conditions for the optimality of full annuitization under market completeness which are substantially less restrictive than those used by Menahem E. Yaari (1965). We examine demand with market incompleteness, finding that positive annuitization remains optimal widely, but complete annuitization does not. How uninsured medical expenses affect demand for illiquid annuities depends critically on the timing of the risk. A new set of calculations with optimal consumption trajectories very different from available annuity income streams still shows a preference for considerable annuitization, suggesting that limited annuity purchases are plausibly due to psychological or behavioral biases.