Joint Committee on Taxation, 593 Ford House Office Building, 416 3rd Street SW, Washington, DC 20515, USA.
Milbank Q. 2011 Dec;89(4):694-727. doi: 10.1111/j.1468-0009.2011.00647.x.
The existence of a positive relationship between income and morbidity has been well documented in the literature. But it is unclear whether the relationship is positive because increased income allows individuals to purchase more health inputs that improve their health, because healthy individuals are more productive and thus can earn higher wages in the labor market, or because a third factor is improving health and increasing income. This article explores whether increases in income improve the health of the low-income population.
Because health status may affect income, this article uses an "instrumental variable" strategy that considers income variations over seventeen years of changes in the generosity of state and federal Earned Income Tax Credits (EITC, a measure that should be exogenous to health status). I measured health status using both the self-reported health status and the functional limitations indicated on the Survey of Income and Program Participation (SIPP), as well as the self-reported health status indicated on the March Current Population Survey (CPS).
I found only limited support for the theory that the relationship between income and morbidity is derived from shifts in income. Although I did observe a correlation between income and self-reported health, I found no evidence that increases in income significantly improve self-reported health statuses. In addition, while increases in income appear to reduce the prevalence of hearing limitations when using corrective measures, these increases did not have a significant effect on most of the other functional limitations considered here.
These findings suggest that the ability to improve short-term health outcomes through public transfer payments may be limited. However, the lifetime effects on the health of people with higher incomes would still be a valuable avenue for future research.
收入与发病率之间存在正相关关系，这在文献中已有充分记载。但目前尚不清楚这种关系是正相关，是因为收入增加使个人能够购买更多改善健康的健康投入，还是因为健康的人更有生产力，因此可以在劳动力市场上获得更高的工资，或者是因为第三个因素在改善健康和增加收入。本文探讨了收入增加是否能改善低收入人群的健康状况。
由于健康状况可能会影响收入，因此本文采用了“工具变量”策略，考虑了 17 年来收入变化对州和联邦所得税抵免（EITC）慷慨程度的变化，EITC（一种应该与健康状况无关的衡量标准）。我使用自我报告的健康状况和收入和计划参与调查（SIPP）上显示的功能限制以及三月份当前人口调查（CPS）上自我报告的健康状况来衡量健康状况。
我仅发现了有限的证据支持收入与发病率之间的关系源自收入变化的理论。尽管我确实观察到了收入与自我报告的健康状况之间存在相关性，但我没有发现证据表明收入增加会显著改善自我报告的健康状况。此外，虽然收入增加似乎可以通过矫正措施降低听力障碍的发生率，但这些增加对这里考虑的大多数其他功能限制没有显著影响。
这些发现表明，通过公共转移支付提高短期健康结果的能力可能有限。但是，对于收入较高的人的健康的终身影响仍然是未来研究的一个有价值的途径。
