College affirmative action bans and smoking and alcohol use among underrepresented minority adolescents in the United States: A difference-in-differences study

BackgroundCollege affirmative action programs seek to expand socioeconomic opportunities for underrepresented minorities. Between 1996 and 2013, 9 US states—including California, Texas, and Michigan—banned race-based affirmative action in college admissions. Because economic opportunity is known to motivate health behavior, banning affirmative action policies may have important adverse spillover effects on health risk behaviors. We used a quasi-experimental research design to evaluate the association between college affirmative action bans and health risk behaviors among underrepresented minority (Black, Hispanic, and Native American) adolescents.Methods and findingsWe conducted a difference-in-differences analysis using data from the 1991–2015 US national Youth Risk Behavior Survey (YRBS). We compared changes in self-reported cigarette smoking and alcohol use in the 30 days prior to survey among underrepresented minority 11th and 12th graders in states implementing college affirmative action bans (Arizona, California, Florida, Michigan, Nebraska, New Hampshire, Oklahoma, Texas, and Washington) versus outcomes among those residing in states not implementing bans (n = 35 control states). We also assessed whether underrepresented minority adults surveyed in the 1992–2015 Tobacco Use Supplement to the Current Population Survey (TUS-CPS) who were exposed to affirmative action bans during their late high school years continued to smoke cigarettes between the ages of 19 and 30 years. Models adjusted for individual demographic characteristics, state and year fixed effects, and state-specific secular trends. In the YRBS (n = 34,988 to 36,268, depending on the outcome), cigarette smoking in the past 30 days among underrepresented minority 11th–12th graders increased by 3.8 percentage points after exposure to an affirmative action ban (95% CI: 2.0, 5.7; p 0.001). In addition, there were also apparent increases in past-30-day alcohol use, by 5.9 percentage points (95% CI: 0.3, 12.2; p = 0.041), and past-30-day binge drinking, by 3.5 percentage points (95% CI: −0.1, 7.2, p = 0.058), among underrepresented minority 11th–12th graders, though in both cases adjustment for multiple comparisons resulted in failure to reject the null hypothesis (adjusted p = 0.083 for both outcomes). Underrepresented minority adults in the TUS-CPS (n = 71,575) exposed to bans during their late high school years were also 1.8 percentage points more likely to report current smoking (95% CI: 0.1, 3.6; p = 0.037). Event study analyses revealed a discrete break for all health behaviors timed with policy discussion and implementation. No substantive or statistically significant effects were found for non-Hispanic White adolescents, and the findings were robust to a number of additional specification checks. The limitations of the study include the continued potential for residual confounding from unmeasured time-varying factors and the potential for recall bias due to the self-reported nature of the health risk behavior outcomes.ConclusionsIn this study, we found evidence that some health risk behaviors increased among underrepresented minority adolescents after exposure to state-level college affirmative action bans. These findings suggest that social policies that shift socioeconomic opportunities could have meaningful population health consequences.背景：大学平权行动（affirmative action）旨在扩大代表性不足少数群体的社会经济机会。1996年至2013年间，美国共有9个州——包括加利福尼亚州、得克萨斯州和密歇根州——禁止在大学招生中采用基于种族的平权行动。鉴于已有研究表明经济机会会影响健康行为，禁止平权行动政策可能会对健康风险行为产生重要的负面溢出效应。本研究采用准实验研究设计，评估大学平权行动禁令与代表性不足少数群体（黑人、西班牙裔及美国原住民）青少年的健康风险行为之间的关联。方法与结果：本研究采用来自1991—2015年美国全国青少年危险行为调查（Youth Risk Behavior Survey, YRBS）的数据开展双重差分（Difference-in-differences）分析。我们比较了实施大学平权行动禁令的州（亚利桑那州、加利福尼亚州、佛罗里达州、密歇根州、内布拉斯加州、新罕布什尔州、俄克拉荷马州、得克萨斯州及华盛顿州）与未实施禁令的州（共35个对照州）的代表性不足少数群体11年级和12年级学生，在调查前30天自我报告的吸烟与饮酒行为变化。此外，我们还通过1992—2015年当前人口调查烟草使用补充模块（Tobacco Use Supplement to the Current Population Survey, TUS-CPS）的数据，评估了在高中晚期暴露于平权行动禁令的代表性不足少数群体成年人，在19—30岁期间是否仍有吸烟行为。研究模型对个体人口统计学特征、州和年份固定效应以及州特异性长期趋势进行了调整。在YRBS样本（因结局指标不同，样本量为34988至36268）中，暴露于平权行动禁令后，代表性不足少数群体11—12年级学生过去30天内的吸烟率上升了3.8个百分点（95%置信区间：2.0, 5.7；p<0.001）。此外，该群体过去30天的饮酒率上升了5.9个百分点（95%置信区间：0.3, 12.2；p=0.041），过去30天的暴饮率上升了3.5个百分点（95%置信区间：-0.1,7.2；p=0.058）；不过在对多重比较进行校正后，这两项结局均未能拒绝原假设（两项结局的校正后p值均为0.083）。在TUS-CPS样本（n=71575）中，高中晚期暴露于禁令的代表性不足少数群体成年人，当前吸烟的概率也高出1.8个百分点（95%置信区间：0.1,3.6；p=0.037）。事件研究分析显示，所有健康行为均出现了与政策讨论和实施时间相匹配的显著突变。未在非西班牙裔白人青少年中观察到具有实质意义或统计学显著性的效应，且研究结果在多项额外的模型设定检验中保持稳健。本研究的局限性包括：仍可能存在未观测到的时变因素带来的残余混杂，以及健康风险行为结局基于自我报告所带来的回忆偏倚风险。结论：本研究发现，在州级大学平权行动禁令实施后，代表性不足少数群体青少年的部分健康风险行为有所增加。上述研究结果表明，改变社会经济机会的社会政策可能会对人群健康产生显著影响。