即使是公告也很重要吗？碳边界调整机制对出口行为的影响

Even the Announcement Matters? The Effect of the Carbon Border Adjustment Mechanismon Exporter BehaviorPublic Disclosure Authorized Uğur AytunGunhild BergSeyit Mümin CilasunEtkin Ozen Financial Services Sector Global DepartmentApril 2026 Policy Research Working Paper11366 Abstract markets. In contrast, the analysis finds no correspondingchanges in export prices, suggesting that firms adjust quan-tities and destinations rather than pricing. The paper furthershows that higher exposure is associated with a lower likeli-hood and lower levels of sourcing green investment inputs,relative to less exposed firms in the post-announcementperiod, both from foreign and domestic suppliers. Thissuggests that there is limited short-run adjustment alongthe green investment margin. Heterogeneity analyses showthat export reallocation responses are stronger among largerand financially unconstrained firms, whereas adjustmentsalong the green investment margin remain limited acrossfirm types. Overall, the results suggest that, in the short run,firms respond primarily to the anticipated costs of CBAMby switching markets rather than upgrading production. This paper studies how firms respond to the announce-ment of the European Union’s Carbon Border AdjustmentMechanism (CBAM), focusing on Turkish manufactur-ing firms with substantial exposure to the EU market.Exploiting variation in firms’ pre-announcement expo-sureto CBAM-covered exports,the paper estimatesdifference-in-differences models using detailed firm–prod-uct–destination trade data. The findings show that moreexposed firms exhibit relatively lower post-announcementexports of CBAM-covered products to the European Union(EU) and relatively higher exports to non-EU destinations,consistent with a market-switching response. These dif-ferences are economically meaningful: a one–standarddeviation increase in exposure is associated with a 3.2 per-cent lower post-announcement level of CBAM exports tothe EU and a 5.5 percent higher level of exports to non-EU The Policy Research Working Paper Series disseminates the findings of work in progress to encourage the exchange of ideas about developmentissues. An objective of the series is to get the findings out quickly, even if the presentations are less than fully polished. The papers carry thenames of the authors and should be cited accordingly. The findings, interpretations, and conclusions expressed in this paper are entirely thoseof the authors. They do not necessarily represent the views of the International Bank for Reconstruction and Development/World Bank andits affiliated organizations, or those of the Executive Directors of the World Bank or the governments they represent. Even the Announcement Matters? The Effect of theCarbon Border Adjustment Mechanism on ExporterBehavior* U˘gur Aytun†,Gunhild Berg‡,Seyit M¨umin Cılasun§,Etkin Ozen¶ Keywords:CBAM, firm behavior, market-switching, trade and environmentJEL Classification:F14, F18, D22, Q56 1Introduction The green transition has become an important policy agenda for many countries andregions across the globe. In response to rising greenhouse gas emissions, an increasingfrequency of extreme weather events, and the cumulative impact of long-term ecologicaldamage, policies are introduced to counter these trends and incentivize economic actorsto change their behaviors. Studying the response of economic actors, in particular firms,to the introduction of one of the most significant of such policies – the introduction of theCarbon Border Adjustment Mechanism (CBAM) in the European Union (EU) – is at thecore of this paper’s contribution. The EU has taken a leading role in global climate action through the European Green Deal,its flagship policy framework for making the EU climate-neutral by 2050. A cornerstoneof this strategy is the EU Emissions Trading System (EU ETS), which operates on a cap-and-trade principle and has been instrumental in reducing emissions from high-pollutingindustries within EU borders. However, as climate ambitions have intensified, concernshave grown over ”carbon leakage”, a phenomenon where emission-intensive productionshifts to countries with looser environmental regulations, potentially undermining globalmitigation efforts and undermining the competitiveness of EU industries. The EU’s CBAM, introduced under the ”Fit for 55” reform under the EU Green Dealannounced on July 14, 2021, aims to address carbon leakage, encourage cleaner industrialproduction worldwide, and preserve industrial competitiveness in the EU. CBAM aims tolevel the playing field by imposing a comparable carbon cost on the emissions embeddedin selected imported goods in the same way as applicable to domestic producers underthe ETS (Maliszewska et al., 2025). Initially, the mechanism covers a limited but highlyemission-intensive set of sectors deemed at high risk of carbon leakage, namely cement,iron and steel, aluminum, fertilizers, hydrogen, and electricity. During the transition