Pollution pictures: Psychological exposure to pollution impacts worker productivity in a large-scale field experiment

While contemporaneous exposure to polluted air has been shown to reduce labor supply and worker productivity, little is known about the underlying mechanisms. We present first causal evidence that psychological exposure to pollution – the “thought of pollution” – can influence employment performance. Over 2000 recruits on a leading micro-task platform are exposed to otherwise identical images of polluted (treated) or unpolluted (control) scenes. Randomization across the geographically-dispersed workforce ensures that treatment is orthogonal to physical pollution exposure. Treated workers are less likely to accept a subsequent offer of work (labor supply) despite being offered a piece-rate much higher than is typical for the setting. Conditional on accepting the offer, treated workers complete between 5.1% to 10.1% less work (labor productivity) depending on the nature of their assigned task. We find no effect on work quality. Suggestive evidence points to the role of induced negative sentiment. Decrements to productivity through psychological mechanisms are plausibly additional to any from physical exposure to polluted air.