The effects of Vietnam-era military service on the long-term health of veterans: A bounds analysis
利用抽签征兵作为工具变量，分析越战时期兵役对美国退伍军人短期和长期健康的影响，发现志愿者在战后约10年出现显著健康损害，而应征者无一致证据。
We analyze the short- and long-term effects of the U.S. Vietnam-era military service on veterans' health outcomes using a restricted version of the National Health Interview Survey 1974-2013 and employing the draft lotteries as an instrumental variable. We conduct inference on the health effects of military service for individuals who comply with the draft-lotteries assignment (the "compliers"), as well as for those who volunteer for enlistment (the "always takers"). The causal analysis for volunteers, who represent over 70% of veterans, is novel in this literature that typically focuses on the compliers. Since the effect for volunteers is not point-identified, we employ sharp nonparametric bounds that rely on a mild mean weak monotonicity assumption. We examine a large array of health outcomes and behaviors, including mortality, up to 38 years after the end of the Vietnam War. We do not find consistent statistical evidence of detrimental health effects on compliers, in line with prior literature. For volunteers, however, we document that their estimated bounds show statistically significant detrimental health effects that appear around 10 years after the end of the conflict. As a group, veterans experience similar statistically significant detrimental health effects from military service. These findings have implications for policies regarding compensation and health care of veterans after service.