Progressive Optimal Technology-based Border Carbon Adjustment (POT BCA) - A New Approach to an Old Carbon Problem

The idea of Border Carbon Adjustment (BCA), which makes it possible to transform the standard tax on carbon emissions from production (origin principle) to a tax system imposed at the point of consumption (destination principle), has received a considerable amount of attention from academia and policymakers. In this paper, we go back to the source of environmental destination-based taxation and generalize the results of Markusen (Journal of International Economics, 5, 15–29, 1975) for optimal tax and tariff by extending domestic environmental policy on both goods featuring positive carbon intensities. Following Jakob et al. (Environmental and Resource Economics, 56(1), 47–72, 2013) we remove the strategic term from the optimal tariff and deal with the so-called optimal carbon tariff, targeting primarily environmental externality. Further, we develop a handy approximation for optimal tax and optimal carbon tariff structure in a multiple good setting. Such trade taxation is, however, likely to face further legal obstacles, which may hinder its implementation. This motivates us to adjust the results accordingly and to include refunds for low-carbon investments in a ‘dirty’ country granted proportionally to the difference in carbon intensities between trade partners. This new scheme, known as Progressive Optimal Technology-based Border Carbon Adjustment (POT BCA), mitigates several legal problems and increases political acceptance compared to the ‘standard’ BCA. It can also be seen as advantageous from the economic point of view: it mimics the performance of the optimal carbon tariff while aiming to decrease foreign carbon intensity over the long term.