Optimal Investment in Health when Lifetime is Stochastic, or, Rational Agents do not Often Follow Health Agency Recommendations

Abstract

A health-capital model is contemplated which accounts for the consumption of many goods, a stock of health and investment in it, as well as an agent’s random lifetime and accumulation of wealth. It is shown that if an agent maximizes the expected discounted value of lifetime utility, or if an agent maximizes the expected value of their lifetime, then an agent does not follow the health-investment policy that minimizes the conditional probability of dying at each point in time, in general. What is more, simple and intuitive sufficient, and necessary and sufficient, conditions are identified whereby such agents investment more or less in their health than said policy.