The health consequences of excess emissions: Evidence from Texas

Excess emissions are air pollution releases that exceed permitted levels and occur during facility start-ups, shutdowns, or malfunctions. While they are violations of the federal Clean Air Act, states have historically granted violating facilities automatic exemptions; limiting enforcement and weakening existing regulation. Recent efforts to harmonize state and federal rules have ignited debate surrounding optimal excess emissions regulation. Using Texas data from 2002 to 2017, we show robust evidence on the costs of excess emissions. We find that excess emissions increase harmful nearby pollution and elderly mortality, and are responsible for an average of 35 annual deaths in Texas alone. Using excess emissions as an instrument for ozone concentrations, we find that a 10% increase in monthly average ozone increases elderly mortality by 3.9%, driven by increased deaths in the oldest age groups.