Border Carbon Adjustments When Carbon Intensity Varies across Producers: Evidence from California

Governments taxing carbon emissions within their jurisdiction can impose a commensurate tax on emissions embodied in imports in order to mitigate emissions leakage. California offers a rare opportunity to investigate how such a border carbon adjustment (BCA) is working in practice. Experience to date highlights important tensions between greenhouse gas accounting accuracy, market efficiency, and concerns about trade protectionism. We simulate electricity market outcomes under BCA designs that differ in terms of how the carbon intensity of imports is assessed. Simulations suggest significant potential for leakage via resource shuffling. Realized emissions outcomes indicate that this potential has not been fully realized.

Strategic Behavior and Market Design in Regional Climate Policy

U.S. electricity markets vary by region and imperfectly overlap with regional climate policies. Although emissions leakage across emissions-regulated and -unregulated areas may depend on regional market design, and the extent of trading between market designs, previous studies of leakage from regional climate policies have focused on market power and market efficiency within only a centralized region following market rules. I develop a theoretical model which considers a second-best problem where a climate policy to correct for a negative externality from carbon emissions can be distorted by another market failure from the market design itself. My model allows for several types of non-overlapping climate policies and electricity market designs, and generates leakage predictions for these combinations.

Challenges in the Measurement of Leakage Risk

Concerns about emissions leakage, i.e., the increase in emissions in foreign jurisdictions induced by a domestic emissions regulation, loom large in debates about unilateral climate change policy. Correctly identifying the kinds of economic activities most at risk of carbon leakage is a critical first step in the design of effective leakage mitigation. We briefly summarize current approaches to assessing leakage risk and highlight a sizable gap between academic research and real-world policy implementation. An emerging research agenda that aims to close this gap is discussed.