The recent evolution and cause-specific drivers of the U.S. Mortality crisis by area-level income in comparison withpeer countries

The National Institute on Aging awarded the National Bureau of Economic Research $576,783 on August 15, 2026, under the Aging Research program (CFDA 93.866) to analyze recent evolution and cause-specific drivers of the U.S. mortality crisis by area-level income in comparison with peer countries.

The research will address income-driven disparities in U.S. mortality and the country's declining life expectancy relative to peer nations, filling gaps in existing literature that largely excludes infants, children, and youth despite evidence that early-life conditions shape lifelong outcomes. The project will use restricted administrative data on the universe of U.S. deaths between 1990 and 2028 and apply a replicable, uniform, fine-grained area-level approach to measure mortality differences by income and trends across all ages, by causes of death, and in harmonized data from peer countries. The research will also examine health conditions driving class gaps in the United States and the country's collective decline relative to peer nations.

Work is performed in Cambridge, Massachusetts. The period of performance extends from the award date through June 30, 2030.

Abstract

The united states is experiencing a compounding mortality crisis, marked by widening income gaps in mortality and an increasing lag in life expectancy relative to peer countries. These trends have been concerning for a long time and are at the center of a vast literature spanning public health, economics, demography, and epidemiology. Despite the importance and urgency of the problem, central questions about income differences in mortality and their role in the broader evolution of U.S. Mortality remain unanswered. Most existing research on income gaps in mortality trends excludes infants, children, and youth, despite the well-established role of earlylife conditions in shaping lifelong outcomes and some earlier research suggesting that younger americans experienced narrowing income gaps in mortality at the same time that gaps widened among adults. Similarly, while few studies have compared these U.S. Trends to those in peer countries, recent work shows that U.S. Life expectancy fell behind that not only for poorer but also for richer americans when compared to similarly ranked populations in europe, suggesting that the american mortality crisis is not restricted to low-income populations but is instead impacting society as a whole. Moreover, the health conditions driving the class gaps in the united states as well as the country's collective decline relative to peer countries are poorly understood. This project will fill these knowledge gaps using the most recent, restricted, administrative data on the universe of deaths between 1990 and 2028 in the united states and a replicable, uniform, finegrained area-level approach to measure mortality differences by income and their trends across all ages, by causes of death, and in harmonized data from peer countries. In collaboration with the national center for health statistics the project team will analyze county-level and census tract-level data, stratify by education and demographic characteristics, examine state-level heterogeneity, and explore associations with area-level characteristics to study recent trends and income gaps in mortality for the whole U.S. Population. We will replicate this area-level analysis in harmonized data provided by (separately funded) research teams in 12 european peer countries and conduct a comprehensive cause-of-death analysis to examine the health conditions underlying the american mortality crisis. By integrating contemporary county- and CT-level data, cause-of-death decompositions, and harmonized international comparisons, the project will weave together, in unprecedented detail, multiple lines of inquiry to provide up-to-date insights into U.S. Mortality trends and their international comparisons. These insights will be key for addressing the health problems that are driving the current crisis.