Using difference-in-differences and a novel break-detection approach I show that the introduction of a carbon tax has not ‘yet’ led to a significant reduction in aggregate CO2 emissions in British Columbia, Canada. Despite the lack of detectable aggregate effect, there are heterogeneous emission reductions across sectors: the tax led to a reduction in emissions from transportation incl. personal vehicles (-5%), buildings (-5%), waste processing (-3%), and light manufacturing, construction and forestry (-11%). Introducing a new method to assess policy based on breaks in difference-in-differences fixed effect panel models, I demonstrate that neither the carbon tax, nor the carbon price and emissions trading schemes introduced in other Canadian provinces are detected as significant interventions in aggregate emissions. The absence of significant aggregate reductions in emissions is consistent with existing evidence that current carbon taxes (and prices) are too low to be effective.
Since current carbon taxes are already not so popular, I don’t take this as especially good news. For the pointer I thank Warren Smith.