The Untranslated Billions: Why Implicit Carbon Costs Deserve Recognition Under CBAM Article 9

Abstract

The European Union's Carbon Border Adjustment Mechanism entered its definitive phase on January 1, 2026, requiring importers to purchase certificates for embedded carbon in steel, aluminum, cement, fertilizers, hydrogen, and electricity. Article 9 of the CBAM Regulation permits deduction of carbon costs "effectively paid in any form" in the country of origin, yet Commission implementing guidance has to date recognized only explicit carbon taxes and emissions trading system payments. This narrow interpretation systematically excludes a population of implicit instruments that exporting economies have built over decades to impose costs on carbon-intensive activity through channels other than nominal carbon pricing.

The companion paper to this volume identifies three distinct forms through which the recognition gap operates: implicit instruments falling outside eligibility criteria (Form A), explicit carbon markets whose allocation design reduces the Article 9 numerator to a small fraction of nominal market prices (Form B), and definitional incompatibilities at the unit level that prevent bilateral reconciliation even in principle (Form C). This paper takes Form A as its focus and develops a cross-country analysis across five major exporting economies. The analysis locates implicit instruments in each country's institutional context, examines why the recognition gap takes different shapes in each configuration, and confronts directly the methodological question of how diverse instruments can be translated into carbon-equivalent values without surrendering precision to the demands of administrative simplicity.

The cross-country evidence points to a structural feature that conventional analyses of CBAM have tended to obscure. Two countries with similar fuel excise regimes at the statutory level can face CBAM costs that differ by an order of magnitude. Exemptions, industrial technology inheritance, and the interaction between the two determine the border-level outcome. Policy ambition, in the sense usually meant when the term is used, plays a smaller role than the current CBAM framing assumes. Recognizing implicit carbon costs through translation protocols would not close the technology gap, but it would acknowledge policy effort that passes through channels other than nominal carbon pricing, and would ease the double-counting burden that currently falls on exporters whose climate governance does not conform to the EU template.

Translation cannot operate without a methodological response to measurement uncertainty. We develop a precision-adjustment framework in which the tariff basis a CBAM declarant may claim is computed as B = μ + k·σ, where μ is the reported carbon-equivalent value of the exporter's implicit cost, σ captures the uncertainty in that estimate, and k is a penalty factor calibrated through bilateral pilot experience. The framework lets countries retain their domestic accounting practices while giving the EU a way to discipline overstatement at the border. The 2026 through 2028 window, before free allowance phase-out accelerates, offers the most favorable conditions for testing translation methodologies in pilot form and feeding their outputs into the Commission's pending implementing act on default carbon prices.