SPECIFIC AIMS Tradeoffs Between the Equal and Equitable Distribution of a Scarce Health Resource: Evidence from a Large Randomized Natural Experiment with Targeting by Health, Social Vulnerability, and Race The recent pandemic and supply chain disruptions have created scarcities in life-saving health resources from ventilators to vaccines, highlighting the need for evidence-based guidance on how to navigate tradeoffs in distributing them. Policymakers have taken several approaches, from giving them to those that request them first, to holding lotteries, to targeting vulnerable populations. Policy responses to scarcity have important implications for large and widening disparities by health, social vulnerability, and race. Our objective is to use economics to analyze a critical period when vaccines were scarce, and policymakers faced a tradeoff between two key goals. One is equality: the same chance at early access for all subgroups of a population. Another is equity: the same average outcomes for all subgroups of a population. Little is known about the extent to which takeup inequities persist given randomized equal distribution, which mechanisms drive them, and how they affect inequities in health and economic wellbeing. Our expertise and setting make us uniquely positioned to overcome a major barrier to understanding tradeoffs between the equal and equitable distribution of vaccines and other scarce health resources by applying rigorous methods from economics to a credible research design. We harness random assignment of early access to vaccines to a large population through Michigan Medicine, a large hospital system with national reach, early in the pandemic when doses were scarce. As emphasized in our letter of support from a core leader of the distribution effort, the initial goal was equality. About 17,000 of >133,000 eligible patients age =65 were randomly assigned to early access in January 2021 before supply unexpectedly dwindled. After invitees had sufficient time to be fully vaccinated and large takeup disparities became clear, the goal shifted to equity. Further rounds of randomized early access were targeted by zip code social vulnerability and individual self-reported race, in accordance with state guidance. Later rounds targeted younger adults in poor health using age ranges and conditions such as Alzheimers Disease and Related Dementias (ADRD) and respiratory disease. We can now examine years of detailed followup data. Aim 1. Estimate inequities in vaccine takeup along many detailed dimensions of health, social vulnerability, and race using equality in early access via random assignment and rich data that we construct and disseminate. We are constructing a large novel dataset by linking randomized invitations to electronic health records, pre-randomization survey data on risk factors and mitigation behaviors during the pandemic, and population-level data from vaccination, death, salary, and voter registries, which we will share. Our preliminary analyses show that an equal distribution of invitations can increase inequities. We will contextualize inequities from our randomized setting using national population-level vaccination, health, and voter data to inform the impact of further policies that target by geographic vs. individual characteristics. Aim 2. Quantify how much of the inequities by health, social vulnerability, and race that persist given equality in early access via random assignment can be explained by various mechanisms that operate through health behaviors, health conditions, and social and environmental factors available in our electronic health records and survey data. We extend the literature by using randomization and rich data to examine mechanisms suggested by our experts in vaccination, sociology, and medicine. Our preliminary analysis shows that distance to vaccination sites can explain about a third of the takeup inequity we find by zip code social vulnerability. Our results will
