Meer Jonathan, Miller Douglas L, Rosen Harvey S
Department of Economics, Stanford University, Stanford, CA 94305, USA.
J Health Econ. 2003 Sep;22(5):713-30. doi: 10.1016/S0167-6296(03)00059-6.
The causal links between health and economic resources have long concerned social scientists. We use four waves of data from the Panel Study of Income Dynamics (PSID) to analyze the impact of wealth upon an individual's health status. The difficulty in approaching this task that has bedeviled previous studies is that wealth may be endogenous; a priori, it is just as likely that changes in health affect wealth as vice versa. We argue that inheritance is a suitable instrument for the change in wealth, and implement a straightforward instrumental variables strategy to deal with this problem. Our results suggest that the causal relationship running from wealth to health may not be as strong as first appears. In the data, wealth exerts a positive and statistically significant effect on health status, but it is very small in magnitude. Instrumental variables estimation leaves the point estimate approximately the same, but renders it insignificantly different from zero. And even when the point estimate is increased by twice its standard error (S.E.), the quantitative effect is small. We conclude that the wealth-health connection is not driven by short run changes in wealth.
健康与经济资源之间的因果联系长期以来一直是社会科学家关注的问题。我们使用收入动态面板研究（PSID）的四轮数据来分析财富对个人健康状况的影响。困扰以往研究的这项任务的难点在于财富可能是内生性的；先验地说，健康变化影响财富的可能性与财富影响健康的可能性一样大。我们认为遗产是财富变化的一个合适工具，并实施了一种直接的工具变量策略来处理这个问题。我们的结果表明，从财富到健康的因果关系可能并不像最初看起来那么强。在数据中，财富对健康状况有正向且在统计上显著的影响，但幅度非常小。工具变量估计使点估计大致相同，但使其与零没有显著差异。而且即使将点估计增加两倍其标准误差（S.E.），定量影响也很小。我们得出结论，财富与健康的联系不是由财富的短期变化驱动的。
