This article studies the long-run effects of government-led construction of manufacturing plants on the regions where they were built and on individuals from those regions. Specifically, we examine publicly financed plants built in dispersed locations outside of major urban centers for security reasons during the U.S. industrial mobilization for World War II. Wartime plant construction had large and persistent effects on local development, characterized by an expansion of relatively high-wage manufacturing employment throughout the postwar era. These benefits were shared by incumbent residents; we find men born before World War II in counties where plants were built earned $1,200 (in 2020 dollars) or 2.5% more per year in adulthood relative to those born in counterfactual comparison regions, with larger benefits accruing to children of lower-income parents. The balance of evidence suggests that these individuals benefited primarily from the local expansion of higher-wage jobs to which they had access as adults, rather than because of developmental effects from exposure to better environments during childhood.

For whom has earnings risk changed, and why? We answer these questions by combining the Kalman filter and EM algorithm to estimate persistent and temporary earnings for every individual at every point in time. We apply our method to administrative earnings linked with survey data. We show that since the 1980s, persistent earnings risk rose by 12.5 percent for both employed and unemployed workers and the scarring effects of unemployment doubled. At the same time, temporary earnings risk declined. Using education and occupation codes, we show that rising persistent earnings risk is concentrated among high-skill workers and related to technology adoption.