Clean Air and Cognitive Productivity: Effect and Adaptation

We observe 1.8 million university course grades for 88,959 adults who learn and complete examinations in a much less polluted environment than previously studied. We use a within-student identification strategy and find robust evidence of a negative and causal effect of exam-day outdoor air pollution on course performance. The effect of pollution persists beyond the same-day effect. Female students are more sensitive than males, and effects are greatest when students are engaged in unfamiliar tasks. We explore two margins of adaptation, one infrastructural, one behavioral. Working in a new building, and particularly if it is high quality (LEED Gold), provides significant mitigation. Relocating to a floor above ground level also offers partial protection.