From theory to practice: determining emissions in traded goods under a border carbon adjustment
探讨欧盟碳边境调整机制（CBAM）的设计，指出基于默认碳强度的调整会扭曲减排激励，而要求生产者提供实际碳强度虽能改善经济和法律效果，但增加行政复杂性并带来资源转移等规避风险。
Abstract As part of its Green Deal, the European Union has advanced a ‘Carbon Border Adjustment Mechanism’ (CBAM). Reflective of a trend towards greater use of coercive trade measures to advance environmental and other policy objectives, the CBAM would extend carbon pricing to imported goods with the aim of limiting carbon leakage. Theoretical enquiry into this type of policy approach—known as border carbon adjustments (BCAs)—suggests economic and environmental benefits, but typically discounts the role of legal and practical constraints on BCA design and implementation. In this paper, we show why the BCA design commonly featured in past research—basing the adjustment level on default carbon intensities—runs counter to the economic logic of carbon pricing by distorting the incentives for emissions abatement. Requiring producers to demonstrate their actual carbon intensity captures additional economic benefits of carbon pricing and improves the overall legal prospects of a BCA, but adds to its administrative complexity and creates risk of avoidance practices such as ‘resource shuffling’. What emerges is a more nuanced understanding of BCAs that highlights the challenges when transitioning from theory to practice.