Asymmetric responses to severance tax changes: Coal production in West Virginia

I use aggregate and mine-level data to analyze changes in coal production due to West Virginia imposing a 56 cent per short ton severance tax in 2005, as well as the effect of the tax's subsequent repeal in 2016. To do so, I construct a dataset of quarterly coal production for West Virginia and neighboring control states not exposed to changes in severance tax policy. Difference-in-differences results suggest that the severance tax increase had no significant effect on either aggregate or mine-level production. Conversely, I find that the severance tax decrease led to an 11.8% increase in aggregate coal production and a 24.4% increase in mine-level production.