Migration and Geographic Inequality in Mid-Life Mortality

PROJECT SUMMARY Since 2010, we have observed steep increases in geographic inequality in mortality that have been strongly tied to stalled mortality declines at the prime adult ages (i.e., 25-64). To date, researchers have analyzed the effects of unemployment, prescription drug monitoring programs, changes in cardiometabolic risk, cigarette smoking, education, health care access, state policies, and a number of other factors thought to influence geographic disparities in mortality. One process that has not been examined in relation to rising geographic inequality in mid-life mortality is migration. Migration has enormous potential to impact geographic inequalities in mortality since it not only configures the makeup of an area, but also influences the properties of a place that themselves may impinge on mortality. Thus, this project examines the contribution of international and domestic migration to levels of and trends in mortality and geographic inequality in mortality. Our analyses focus on both inequality within the United States and inequality between the U.S. and other high-income countries. We use vital statistics and census microdata linked to mortality follow-up to assess how international and domestic migration have direct impacts on mortality inequality by concentrating healthy, low-mortality migrants in specific parts of the country, and indirect impacts on non-migrant mortality by reshaping the characteristics of places that have been shown to influence mortality levels. We provide the first subnational estimates of mortality by nativity and the first estimates for the U.S. of the effects of domestic migration on geographic inequality in mid-life mortality. Using a quasi-experimental research design, we identify the causal effect of migration on non-migrants, constituting the first demonstration of the magnitude of spillover effects on U.S. mortality. While countries differ in their proportions foreign-born and in their migration streams, it is not yet known how immigration impacts cross-national inequality in mortality. We investigate how international migration contributes to the U.S. life expectancy shortfall and to variation in mortality across high-income countries, including in measures of life expectancy, mid-life mortality, and lifespan inequality. An important byproduct of this project is that we will release a public database of high-quality life tables for the native-born and foreign-born populations of the U.S. and other high-income countries, as well as a public database of life tables for the native- and foreign-born populations of geographic areas within the United States. This project provides new theoretical knowledge of how people and places respond to migration, and of the multiplicity of dynamic responses of mortality to migration trends. Methodologically, this project builds out a new set of demographic methods that allow model-based heterogeneous mortality rates to be linked to counties on the basis of individual and county-level characteristics. It also applies a set of causal methods that have not previously been used to study mortality in order to model the geographically differentiated spillover effects of migration on mortality.