未来能源研究所：2025年空气净化器在学校的作用报告（英文版）

We randomize the installation of air purifiers across primary school classrooms to reduce children’s exposure to air pollution. The intervention reduces indoor PM2.5 concentrations by 32% and decreases student absenteeism by 12.5%. Effects are larger among students with higher pre-treatment absenteeism. The impact is greater when outdoor air pollution is relatively low and diminishes as outdoor pollution intensifies, consistent with non-linear marginal effects of air quality on health. The tr