When the Rain Falls: Extreme Weather and Urban Labor Supply

Abstract
This paper estimates the effects of extreme rainfall on on-site labor supply using high-frequency mobile phone signaling data from China. Extreme rainfall reduces commuting flows by 4.1% while increasing time spent at the workplace among those who continue to commute. These declines are concentrated on days when rainfall occurs during the morning commute and are more pronounced for longer journeys and along corridors with better metro accessibility. Workers adjust both within and across days, spending more time at home and shifting workplace attendance to subsequent days, including weekends. When measured over rolling time windows, commuting losses largely disappear, but the effect on workplace duration becomes negative. Higher urban drainage density mitigates commuting declines, and a wage-based accounting exercise indicates that each additional kilometer of drainage pipe per square kilometer is associated with a 6% reduction in implied net labor-income losses.Our findings highlight the importance of temporal adjustment in assessing weather-related labor disruption and the potential role of urban infrastructure in climate adaptation.