PROJECT SUMMARY. The economy and the family—two social institutions that strongly affect health and well-being in the US—have undergone profound change in the last half-century. The economy changed through the stagnation of male wages, declining manufacturing jobs and rising service sector employment, and increases in inequality. Simultaneously, US families experienced increases in instability (repeated changes in parental marital/union status) and complexity (families that exist outside the typical nuclear family structure) through the late 1990s, such that approximately 40% of children currently live in complex families. Local economic conditions, like income inequality, are linked with singular family formation behaviors, like nonmarital births. Yet, the relationship between local economic conditions and family instability and complexity remains unknown. The objective of the proposed research project is to assess how local economic conditions— unemployment rates, wage stagnation, occupational structure, and income inequality—are associated with patterns of family instability and complexity, identifying how these associations developed over historical time and vary by social location. Aim 1 will establish contemporary (1997-2017) patterns of family instability and complexity by local economic conditions. Aim 2 will assess how changes in local economic conditions are linked with changes in family instability and complexity over historical time, comparing three periods: 1969- 1975 (early family change), 1976-1996 (rapid family change), 1997-2017 (family change plateau). Aim 3 will assess variation by race and educational attainment in the associations between local economic conditions and family instability and complexity. The PI will use advanced quantitative methods—sequence analysis, demographic decomposition, spatial data analysis, and causal inference techniques—to address these aims, and the use of nationally-representative data will produce generalizable results. Collectively, the aims will generate rigorous evidence on (1) whether and how local economic conditions affect patterns of family structure change, and (2) which children are most likely to be exposed to family instability and complexity. These findings are relevant to population health because family instability and complexity compromise the health and well-being of parents and children. This research project is part of a broader, 3-year postdoctoral training fellowship at a top research university, supervised by a team of mentors with expertise in family demo- graphy and economic inequality. The training plan comprises: (1) substantive training in family demography, economic conditions, and economic inequality; (2) advanced quantitative methods training that will facilitate a career in population health-relevant research; and (3) professional development through increased research independence, grant writing, conference presentations, and networking. The training plan will prepa...