2020年贸易低迷期间的贸易政策和贸易韧性（英）

Alessandro Nicita TradeAnalysisBranchDivisiononInternationalTrade andCommodities UNCTAD alessandro.nicita@un.org EnxhiTresa TradeAnalysisBranchDivisiononInternationalTrade andCommodities UNCTAD enxhi.tresa@un.org Tradepolicyandtraderesilienceduringthe2020tradedownturn Abstract Keywords TheCOVID-19pandemicresultedinlargeandheterogeneousdeclinesinbilateraltradeflows.Thisstudyinvestigateswhetherthesediverseeffectscanbeexplainedbydifferencesintradecostsasmeasuredbypre-existingtradepoliciessuchastariffs,non-tariffmeasures,andparticipationintradeagreements.Resultsindicatethattradeflowssubjecttohighertradecostsdeclinedbymorethanaverageduring2020.Theresultsalsoshowthattheeffectofhighertradecostswaslowerthelargertheimporter’smarketshare.Weinterprettheseresultsasevidencethatthefallindemandduring2020causedless-establishedandhigher-costsupplierstobesqueezedoutofinternationalmarkets.Moregenerally,theresultsofthispaperhaveimportantimplicationsfordevelopment,astheyindicatethatsimilartradecostsimposerelativelyhigherburdensonsmallerexporters. Internationaltrade,COVID-19,tradepolicy,tariffs,non-tariffmeasures,tradeagreements. UNITEDNATIONSCONFERENCEONTRADEANDDEVELOPMENT WORKINGPAPER No.1 UNCTAD/WP/2022/1 NOVEMBER2022 Thefindings,interpretationsandconclusionsexpressedhereinarethoseoftheauthor(s)anddonotnecessarilyreflecttheviewsoftheUnitedNationsoritsofficialsorMemberStates.ThedesignationsemployedandthepresentationofmaterialonanymapinthisworkdonotimplytheexpressionofanyopinionwhatsoeveronthepartoftheUnitedNationsconcerningthelegalstatusofanycountry,territory,city,orareaorofitsauthorities,orconcerningthedelimitationofitsfrontiersandboundaries.Thispaperhasnotbeenformallyedited. Contents Acknowledgements........................................................................................2 1.Introduction.................................................................................................3 2.Dataanddescriptivestatistics..................................................................4 3.EmpiricalAnalysis.......................................................................................6 3.1Tradecostsandmarginsoftrade..................................................6 3.2Heterogeneouseffectoftradecosts..............................................7 4.Results.........................................................................................................7 4.1Tradecostsandtheextensivemarginoftrade.............................7 4.2Tradecostsandtheintensivemarginoftrade..............................8 4.3Heterogeneouseffectsoftradecosts............................................9 5.Conclusions12 References13 Appendix:Sectoralresults14 Acknowledgements ThispaperbenefittedfromcommentsandsuggestionsfromGrahamMott,RalfPeters,CarlosRazoandMesutSaygili.Theauthorsalsothanktwoanonymousreviewersfortheircarefulreadingofthemanuscriptandtheirmanyinsightfulcommentsandsuggestions. 1.Introduction AsaconsequenceoftheCOVID-19pandemic,tradeconsiderablydeclinedformostproductsandcountriesduring2020.ThenegativeimpactofCOVID-19oninternationaltrade,whilewidespread,hasbeenfarfromhomogeneous.Whatfactorscanexplainsuchheterogeneity?Thispaperexploreswhetherpre-existingtradepolicyinfluencedheterogeneousdeclinesinthebilateraltradeflowsobservedin2020. ThispapercontributestotheliteratureontheeffectsofCOVID-19oninternationaltrade1byanalyzingwhetherthechangesininternationaltradeobservedduring2020canberelatedtopre-existingtradepolicy(tariffs,non-tariffmeasuresandtradeagreements).Therationaleforthishypothesisisthatadeclineinglobaldemandwouldaffectinternationaltradeflowsbyforcinglessestablishedandhigher-costsuppliersoutofinternationalmarkets.2 Ourworkalsoaddstotheliteratureonheterogeneouseffectstotradecostsbyinvestigatingwhethersimilartradepolicieshavediverselyaffectedtradeflows,dependingonmarketsharesinimportermarkets.TheanalysisofthispaperfollowstherationaleofChenandNovy(2022),whousegravityequationstoinvestigatetheheterogeneityoftradecosts.Theyfindthattheeffectoftradecostsisstrongerwhenbilateralimportsharesaresmaller.WhileChenandNovy(2022)specificallyinvestigateachangeintradecostsresultingfromtheformationofacurrencyunion,theirrationaleappliestoallformsoftradecosts.ThefactthatthetradeelasticitytendstobeinverselycorrelatedwithimportshareslinkstotherationaleofHelpmanetal.(2008),whofoundthatbilateraltradecostelasticitiesarelargerforlessdevelopedcountries,andMelitzandRedding(2015)whodocumentedthattradeelasticitiesvaryacrossmarketsandlevelsoftradecosts.Carrèreetal.(2020)alsoshowtheimportanceofnon-constanttradeelasticities,byhighlightingdistanceeffects.Otherstudiesalsoshowthattradeagreementsboostinternationaltrade,thoughtheireffectmightbeattenuatedbydistance(HeadandMayer,2014). Thequestionoftheheterogeneouseffectsoftradecostshasbeenextensivelystudiedinthemicro-levelliterature,whichdemonstratesthatknowledgeofthefirm-levelresponsetotradecostsiskeyforunderstandingtherelationbetweenaggregateexportsandtradecosts.Itisshownthattheelasticityoftradeflow