Abstract This paper uses exogenous variation in sleep induced by sunset time to present the first human capital estimates of (i) the effects of child sleep from the developing world and (ii) the long-run effects of child sleep in any context. Later sunset reduces children’s sleep: when the sun sets later, children go to bed later but fail to compensate by waking up later. Sleep-deprived children study less and increase nap time and indoor leisure activities. Short-run sleep loss decreases children’s test scores. Chronic sleep deficits translate into fewer years of education and lower primary and middle school completion rates among school-age children.

Abstract Heat's impact on economic growth and aggregate productivity is well-established, but while individual impairments are well-understood as mechanisms, the role of interpersonal dynamics remain unexplored despite the growing prevalence of team-based occupations. In our experiment, programmers were randomly assigned to work individually or in pairs under warm (29°C) or control (24°C) conditions. We found that heat had no effect on individual performance but impaired team performance—not through decreased effort but likely through impaired collaboration. This negative impact was strongest in heterogeneous teams, suggesting heat exacerbates coordination challenges, confirmed by poorer partner evaluations in warm conditions.