170 Years of Change in Living Arrangements in the United States Using Expected Years of Life: A Research Note
2026-04-08
Over the past 170 years, the United States has undergone demographic, structural, and cultural changes that are reflected in—and a reflection of—changes in living arrangements. In this research note, we link living arrangements and life expectancy to calculate expected life years spent across different living arrangements by sex for the U.S. population for the period 1850–2021. We decompose changes in this measure by age group and describe change across cohorts. We use harmonized data from the Integrated Public Use Microdata Samples, classifying living arrangements into alone, with primary kin only (partners, parents, and children), and in extended households; more detailed subcategories include, for example, single-parent households and extended families. Three historical ages of U.S. living arrangements emerge: a “large household” system (1850–1940) characterized by relative stability in the extended household, when primary kin arrangements incorporate the majority of the substantial gains in life expectancy; an era of “primary kin” dominance (1940–1980) when life years spent only with primary kin increase faster than life expectancy, while the prevalence of extended households declines; and a “diversified” phase (1980–onward) characterized by a decline in two-parent households in favor of greater diversity, including living alone and with extended family.