采用CBO-EPPA模型分析碳进口关税及出口退税政策

UsingtheCBO-EPPA Model to AnalyzeCarbonImportTariffsandExportRebates Gokce Akin-OlcumCongressionalBudget Officegokce.akin-olcum@cbo.gov KennethAustinCastellanosCongressionalBudget Officeaustin.castellanos@cbo.gov March2026 Papers in this series provide technical descriptions of CBO’s official analyses or present independent researchby CBO’s analysts. The papers are produced to enhance the transparency of CBO’s work and encourageexternal review of that work. For a list of papers in the series, seehttp://go.usa.gov/xUzd7. This paper has not been subject to CBO’s regular review and editing process. The views expressed hereshould not be interpreted as CBO’s. For valuable comments, the authors thankAlan Fox of the International Trade Commission andSergeyPaltsevoftheMassachusetts Institute of Technology.The authors also benefited greatly from comments byDorian Carloni, Nicholas Chase,Daniel Fried,AnnE.Futrell, Peter Herman, Joseph Kile,JeffreyKling,Aaron Krupkin, andEmma Uebelhorof CBO.The authors gratefully acknowledge the editorial assistance Abstract In this working paper,weanalyzethe effects ofcarbon import tariffsandexport rebates(implementedalongwith a carbon tax)on sectoral output, trade, and carbon dioxide emissionsand compare them with the effects ofa carbon taxalone.Forthatanalysis,weuseda modifiedversion ofthe Massachusetts Institute of Technology’s Economic Projection and Policy Analysis Using CBO-EPPA, we estimate that implementingacarbon taxwouldreducetheoutput ofenergy-intensive and trade-exposed(EITE)sectorsin 2050by 2.6percent,would decrease thosesectors’ exports in 2050by 2.2percent, andwouldincreaseEITEproductimportsin 2050by0.2percent.By contrast,implementingbothacarbonimporttariffandanexport rebatealongwith a carbon taxwouldincreasetheoutputof affected sectorsin2050by0.2percent,would In addition to detailing those results, thispaper discusseshowcarbon import tariffsandexportrebatescouldbe challenged undertherulesinWorld Trade Organizationtreaties. Keywords:carbondioxide,climate,international trade, tax JEL Classification:F13,F18,Q56, Q58 Notes Numbers in the text, tables, and figures may not add up to totals because of rounding. Unless otherwise specified, alldollar amountsare expressed in 2014dollars,reflecting the base “Emissions”refersto carbon dioxide emissions unless otherwisespecified. In theillustrativepolicy cases,carbon import tariffsandexport rebatesare implemented along Contents Introduction.....................................................................................................................................1Overview of the EPPA Model........................................................................................................2Model Structure..........................................................................................................................2Main Strengths and Limitations of the Model............................................................................3Analyzing Carbon Import Tariffs and Export Rebates Using CBO-EPPA....................................5Policies Analyzed........................................................................................................................7Results.........................................................................................................................................9Sources of Uncertainty..................................................................................................................14WTO Compliance.........................................................................................................................16AppendixA: Calibration of the CBO-EPPA Model.....................................................................18GDP and Population Calibration..............................................................................................18 Introduction To analyze the effects ofcarbonimporttariffsandexport rebates(implementedalongwith acarbon tax)onsectoraloutput, trade, andcarbon dioxide(CO2)emissions,weadopted andmodified theEconomic Projection and Policy Analysis (EPPA) model from theMassachusettsInstitute of Technology’s (MIT’s)Center for Sustainability Science and Strategy.1That model isan open-source, computablegeneral equilibriummodel of the world economy that projectseconomic andemissionsoutcomesover several decades.The version of EPPA thatweadaptedfor this paper is not currently availableto the public, butprevious versions of the model are Weused EPPA to analyzetheeconomic and emissionseffects ofillustrativepolicy cases inwhichcarbon importtariffsandexport rebatesare implemented alongwith a carbon tax.Carbon importtariffsimpose a tax onimportsbasedontheamount ofCO2released duringthoseimports’productionandsupply chainprocesses; thetaxis calculated so that it isequal to thecarbon taxplacedon domestic producers.Carbon export rebates refundthecarbontaxespaidduring thedomesticproductionand supplyofcertainexp