The study evaluated 88 clean-heating pilot cities in northern China between 2013 and 2023, using weather-normalised city-level daily PM2.5 and augmented synthetic control to construct no-policy counterfactuals. Estimated policy effects were -3.01 \u00b5g/m\u00b3 for the heating-season mean, -5.96 \u00b5g/m\u00b3 at P99 and -7.92 exceedance days per season. An exposure-response model attributed 12,454 fewer short-term PM2.5-attributable all-cause deaths (95% CI 8,564-16,222) to improvement days, 56.2% of them in the top 10% of cities.
Why it is interesting: Averages understate what a pollution policy does at the tail of the distribution, which is where the short-term mortality sits.