Is there a case for carbon-based border tax adjustment? An applied general equilibrium analysis

Concern that unilateral Greenhouse Gas (GHG) emission reductions could foster carbon leakage and undermine the international competitiveness of domestic industry has led to growing calls for carbon-based Border-Tax Adjustments (BTAs). This article uses a global general equilibrium model to assess the economic effects of BTAs and comes to three main conclusions. First, BTAs can reduce carbon leakage if the coalition of countries taking action to reduce GHG emissions is small, because in this case leakage (while typically small) mainly occurs through international trade competitiveness losses rather than through declines in world fossil fuel prices. Second, even though the economic effects of BTAs vary somewhat depending on how they are implemented, their welfare impact is typically small, and slightly negative at the world level. Third, and perhaps more strikingly, BTAs do not necessarily curb the output losses incurred by the domestic Energy Intensive-Industries (EIIs) they are intended to protect in the first place. This is in part because EIIs in industrialized countries make important use of carbon-intensive intermediate inputs produced by EIIs in other geographical areas. Another, deeper explanation is that EIIs are ultimately more adversely affected by the existence of a carbon price itself than by any international competitiveness losses. These findings are shown to be robust to key model parameters, country coverage, targets and design features of BTAs.