Carbon pricing with regressive co-benefits: evidence from British Columbia’s carbon tax

I assess the air quality and environmental equity impacts of the 2008 carbon tax in British Columbia. Using high-resolution data and a synthetic difference-in-differences strategy, I find that the carbon tax has reduced PM2.5 emissions by 5.2-10.9%. This result is heterogeneously distributed, with larger reductions in areas with lower baseline pollution, lower population density, lower material deprivation, and higher income. While all areas experience substantial positive co-benefits in terms of reduced air pollution hazard rates, quantified at $198 per capita, my results imply a widening of the pre-existing environmental justice gaps. This dynamic represents an additional dimension of carbon tax regressiveness.