(No) time to be healthy: Optimal policy with time and monetary investments in health
研究考虑时间与货币投入的健康促进最优政策，发现个体低估健康重要性导致投资不足，在信息不对称下，货币健康投资的补贴设计需考虑与时间投资的互补或替代关系，并影响所得税政策。
Time is often an important ingredient of a healthy lifestyle. Starting from this observation, this paper studies optimal public policy concerned with promoting healthy choices taking into account both monetary and time investments in health. Individuals tend to underestimate the importance of their health while making decisions, which makes their investments too low compared to the first-best. While the decentralization of the first-best requires personalized subsidies on both time and monetary investments, this may be problematic due to informational issues. In a second-best world where individual productivities and time investments are publicly unobservable, whereas monetary investments are observable in an anonymous way, the paper considers a policy with a non-linear income tax and a linear subsidy on monetary health investments. If there are no incentive concerns, all other things equal, monetary investments complementary (substitutable) to time investments should be subsidized more (less) than those independent of time use. The addition of incentive concerns demonstrates that optimal subsidization of monetary health investments is less straightforward than one might think. Overall, the time ingredient in the production of health does play a role in the optimal policy design, affecting not only the subsidy on monetary health investments but also the income taxation.