Military deployments and job assignments provide an opportunity to estimate the impact of parental absences and household relocations on children’s academic achievement. Combining U.S. Army personnel data with children’s standardized test scores from Texas, I find that parental absences adversely affect children’s test scores by a tenth of a standard deviation. Likewise, household relocations have modest negative effects on children’s test scores. Both parental absences and household relocations have the greatest detrimental effect on test scores of children with single parents, children with mothers in the army, children with lower‐ability parents, and younger children.

The random assignment of cadets to social groups at West Point provides a rare opportunity to highlight potentially misleading estimates of social group effects found in many studies. Estimates of contemporaneous group effects in human capital production are typically positive and significant; however, evidence in this study suggests that occurrences common to a group may account for much of this correlation. Models that address these biases provide little evidence of group effects in academic performance, although there is evidence of group influences in choice outcomes such as the selection of academic major and the decision to remain in the Army.

Military assignment mechanisms provide a unique opportunity to estimate the impact of high-performing mentors on job advancement of their subordinates. Combining US Army administrative data with officer evaluation reports, we find that high-performing mentors positively affect early junior officer promotion and that early promotion probabilities rise as the duration of the high-quality mentorship increases. These effects are largest for high-ability protégés. Junior officers who were exposed to multiple high-performing mentors did not experience an additional increase in promotion rates.

We exploit the military mobilization for World War II to investigate the effects of female labor supply on the wage structure. The mobilization drew many women into the workforce permanently. But the impact was not uniform across states. In states with greater mobilization of men, women worked more after the war and in 1950, though not in 1940. These induced shifts in female labor supply lowered female and male wages and increased earnings inequality between high school– and college‐educated men. It appears that at midcentury, women were closer substitutes for high school men than for those with lower skills.