Housing policy, neighborhood context, and pathways to midlife mortality in a social experiment - Life expectancy is a key metric of population health. Yet Black and low-income Americans exhibit much shorter life expectancy than their White, Hispanic, and higher-income counterparts. Housing and neighborhood context are key causes of these mortality differences via interlocking, accumulating social determinants of health at multiple levels across the life course. Yet literature examining how neighborhood context affects mortality remains weak methodologically. It relies on ecologic, cross sectional data; lacks a life course approach; ignores heterogeneity; rarely predicts population impact; and is divorced from policy solutions. Policy relevant levers are sorely needed that can disrupt the complex, upstream knot of family impoverishment. Our study of place-based factors leading to mid-life mortality addresses these limitations, leveraging data from a promising housing policy experiment: The Moving to Opportunity (MTO) Study. The MTO follows 4600 low-income families, living in public housing at baseline (1994-98), in five large US cities, who were randomized to receive one of three treatments: one of two types of housing vouchers to improve housing affordability and neighborhood context or an in-place control group that remained in public housing. The original MTO evaluation concluded in 2010, at which time adults randomized to the housing mobility voucher arm (vs. the other two arms) exhibited improved physical and mental health and improved neighborhood exposures. This study expands and enriches the MTO study by linking it to three administrative datasets through 2024, extending the study 15 additional years—(1) NCHS’s National Death Index, (2) Census Bureau/Social Security’s Numident, and (3) the Census Master Address File—allowing us to analyze the effects of housing policy on mid-life mortality and long-term residential mobility. An experienced and productive social epidemiologist and population health scholar leads this accomplished, interdisciplinary team. Our project has four specific aims: Aim 1: Test if the MTO low-poverty neighborhood housing mobility voucher treatment improves neighborhood opportunity in year 2024, vs. the in-place public housing or traditional voucher group; Aim 2: Test if the MTO low-poverty housing voucher treatment reduces mortality risk through mid-life versus the other 2 treatment groups; Aim 3: Test heterogeneity of MTO effects on mortality by baseline demographic factors (i.e., subgroup effects); Aim 4: Calculate the number of deaths that would be avoided and whether the mortality gap would narrow between groups, at the population level, if voucher-based housing policy were broadly implemented to promote opportunity moves. The proposed project aligns with the NIA Population and Social Processes Branch “Macro-Social Factors” priority area, by estimating population level impacts of a randomized social program. Our study presents a unique and important opportunity for population health: to understand whether housing mobility policy can promote sustained moves to high opportunity neighborhoods, and whether such effects may reduce mid-life mortality risk after 30 years.