A Natural Experiment Evaluating the Effect of a Minimum Wage Increase on Obesity and Diet-Related Outcome

最低工资法正越来越多地被认为是一种可能的改善政策杠杆 人口健康和健康公平，有可能在地方、州和国家各级实施。 2017年6月30日，明尼苏达州明尼阿波利斯市成为第40个最低工资高于最低工资标准的地方辖区 州一级。到2022年7月1日，该市将逐步将所有人的最低工资提高到每小时15美元 雇员超过100人的公司；在此期间，较小公司的最低工资将增加到13.50美元 句号。预计该法令将提高7.1万名可能受到影响的工人的工资，这些工人 不成比例的非西班牙裔黑人和西班牙裔工人。现有证据表明，至少 工资法可能与一系列健康后果有关。这包括肥胖，因为增加工资可以 改善粮食安全，减少购买更健康食品的成本限制。然而，现有的研究 将工资和体重联系起来的设计缺陷限制了因果推理和识别因果关系的能力 机械装置。这项研究具有前瞻性的准实验设计，具有很强的反事实 是检验提高最低工资是否以及如何带来改善的下一步 低工资工人中与肥胖相关的结果。在45年的实施过程中 明尼阿波利斯最低工资条例，我们将遵循一批低工资工人(那些收入低于 每小时10美元)，在自然实验中，使用差异设计来比较 明尼阿波利斯市(n=400)低薪工人队列中的肥胖相关测量 匹配对照社区(n=400)，北卡罗来纳州罗利。控制城市有一项全州范围的优先购买法， 禁止提高当地最低工资。所有个人的测量将在基线(T0)及之后收集 5递增工资(T1-T5)，至2022年6月。这项研究的目的是测试在变化中的差异 身体质量指数(BMI，主要结果)在两种情况下的个体之间，由以下评估 人体测量身高和体重。我们还将测试这两种条件变化的差异 一系列与营养相关的结果，包括购买更健康和不太健康的食物(通过 粮食采购收据)、粮食不安全(以美国农业部6项指标衡量)以及参与 政府粮食援助计划(通过参与者调查来衡量)。最后，我们将测试其他行为 以及工资可能影响肥胖的心理社会机制，并探索在 随着时间的推移，与家庭健康相关的费用。最低工资法是一种潜在的上游方法 预防肥胖，这些政策可能在减少健康差距方面具有独特的定位，因为它们 对健康状况不佳风险最高的人群(低收入、高种族/少数民族)进行干预。这 自然实验提供了一个时间敏感的机会来测试政策效果，并贡献了难得的健康导向 透视一项经济政策对国家话语的影响。

Minimum wage laws are increasingly being recognized as a possible policy lever for improving population health and health equity, with the potential for implementation at the local, state, and national levels. On June 30, 2017, Minneapolis, Minnesota became the 40th local jurisdiction to set the minimum wage above the state level. The city will incrementally increase the minimum wage to $15 an hour by July 1, 2022 for all firms with greater than 100 employees; minimum wage in smaller firms will increase to $13.50 during this time period. The ordinance is expected to increase wages among the 71,000 workers likely to be affected, who are disproportionately non-Hispanic black and Hispanic workers. The available evidence suggests that minimum wage laws may be associated with a range of health outcomes. This includes obesity, as increasing wages can improve food security and reduce cost constraints for purchasing healthier foods. However, existing studies linking wages and weight have design weaknesses that limit causal inference and the ability to identify causal mechanisms. This study, which has a prospective quasi-experimental design with a strong counterfactual condition, is the next step for testing whether and how an increase in minimum wage results in improved obesity-related outcomes among low-wage workers. Throughout the 4.5-year implementation of the Minneapolis minimum wage ordinance, we will follow a cohort of low-wage workers (those earning less than $10 an hour at baseline) in a natural experiment, using a difference-in-difference design to compare a panel of obesity-related measures in a cohort of low-wage workers in Minneapolis (n = 400) and similar workers in a matched control community (n = 400), Raleigh, NC. The control city has a statewide preemption law which prohibits local minimum wage increases. Measures for all individuals will be collected at baseline (T0) and after 5 incremental wage increases (T1-T5) through June 2022. The study aims to test the difference in change in body mass index (BMI, the primary outcome) between individuals in the two conditions, as assessed by anthropometric height-weight measurements. We will also test the difference in change in the two conditions for a range of nutrition-related outcomes, including purchases of healthier and less healthy foods (measured by food purchase receipts), food insecurity (measured by a 6-item USDA measure), and participation in government food assistance programs (measured by participant survey). Finally, we will test other behavioral and psychosocial mechanisms through which wages might affect obesity, and explore spending changes in household health-related expenses over time. Minimum wage laws are a potential upstream approach to prevent obesity, and these policies may be uniquely positioned to reduce health disparities because they intervene on a population (lower-income, high racial/ethnic minority) at the highest risk for poor health. This natural experiment offers a time-sensitive opportunity to test policy effects and contribute a rare health-oriented perspective to the national discourse around the effects of an economic policy.