Journal of Economic Perspectives—Volume 24, Number 2—Spring 2010—Pages 163–188 The Columbian Exchange: A History of Disease, Food, and Ideas Nathan Nunn and Nancy Qian hhee CColumbianolumbian ExchangeExchange refersrefers toto thethe exchangeexchange ofof diseases,diseases, ideas,ideas, foodfood ccrops,rops, aandnd populationspopulations betweenbetween thethe NewNew WorldWorld andand thethe OldOld WWorldorld T ffollowingollowing thethe voyagevoyage ttoo tthehe AAmericasmericas bbyy ChristoChristo ppherher CColumbusolumbus inin 1492.1492. TThehe OldOld WWorld—byorld—by wwhichhich wwee mmeanean nnotot jjustust EEurope,urope, bbutut tthehe eentirentire EEasternastern HHemisphere—gainedemisphere—gained fromfrom tthehe CColumbianolumbian EExchangexchange iinn a nnumberumber ooff wways.ays. DDiscov-iscov- eeriesries ooff nnewew ssuppliesupplies ofof metalsmetals areare perhapsperhaps thethe bestbest kknown.nown. BButut thethe OldOld WWorldorld aalsolso ggainedained newnew staplestaple ccrops,rops, ssuchuch asas potatoes,potatoes, sweetsweet potatoes,potatoes, maize,maize, andand cassava.cassava. LessLess ccalorie-intensivealorie-intensive ffoods,oods, suchsuch asas tomatoes,tomatoes, chilichili peppers,peppers, cacao,cacao, peanuts,peanuts, andand pineap-pineap- pplesles wwereere aalsolso iintroduced,ntroduced, andand areare nownow culinaryculinary centerpiecescenterpieces inin manymany OldOld WorldWorld ccountries,ountries, namelynamely IItaly,taly, GGreece,reece, andand otherother MediterraneanMediterranean countriescountries (tomatoes),(tomatoes), IIndiandia aandnd KKoreaorea (chili(chili peppers),peppers), HungaryHungary ((paprika,paprika, mmadeade ffromrom cchilihili ppeppers),eppers), aandnd MMalaysiaalaysia aandnd TThailandhailand (chili(chili ppeppers,eppers, ppeanuts,eanuts, andand pineapples).pineapples). Tobacco,Tobacco, anotheranother NNewew WWorldorld ccrop,rop, wwasas ssoo uuniversallyniversally aadopteddopted tthathat iitt ccameame ttoo bbee uusedsed aass a ssubstituteubstitute fforor currencycurrency iinn mmanyany ppartsarts ofof thethe world.world. TThehe eexchangexchange aalsolso ddrasticallyrastically iincreasedncreased tthehe availabilityavailability ooff mmanyany OOldld WWorldorld ccrops,rops, ssuchuch aass ssugarugar aandnd ccoffee,offee, wwhichhich werewere pparticularlyarticularly well-suitedwell-suited forfor thethe soilssoils ofof thethe NewNew World.World. TThehe exchangeexchange nnotot oonlynly bbroughtrought ggains,ains, bbutut aalsolso llosses.osses. EEuropeanuropean ccontactontact eenablednabled tthehe ttransmissionransmission ooff ddiseasesiseases ttoo ppreviouslyreviously iisolatedsolated ccommunities,ommunities, wwhichhich ■ NNathanathan NNunnunn iiss aann AAssistantssistant PProfessorrofessor ooff EEconomics,conomics, HHarvardarvard UUniversity,niversity, CCambridge,ambridge, MMassachusetts.assachusetts. DuringDuring thethe 2009–20102009–2010 aacademiccademic yyear,ear, hehe waswas thethe TrioneTrione VVisitingisiting PProfessorrofessor ofof EEconomicsconomics aatt StanfordStanford University,University, Stanford,Stanford, California.California. NancyNancy QianQian isis anan AssistantAssistant ProfessorProfessor ooff EEconomics,conomics, YaleYale University,University, NNewew Haven,Haven, CConnecticut.onnecticut. BBothoth aauthorsuthors aarere aalsolso FFacultyaculty RResearchesearch Fellows,Fellows, NNationalational BureauBureau ofof EconomicEconomic ResearchResearch (NBER),(NBER), Cambridge,Cambridge, Massachu-Massachu- ssetts,etts, aandnd AAffiffi lliates,iates, BureauBureau fforor RResearchesearch aandnd EconomicEconomic AnalysisAnalysis ooff DDevelopmentevelopment ((BREAD).BREAD). TTheirheir ee-mail-mail aaddressesddresses aarere 〈[email protected]@fas.harvard.edu〉 aandnd 〈[email protected]@yale.edu〉. doi=10.1257/jep.24.2.163 164 Journal of Economic Perspectives ccausedaused ddevastationevastation ffarar eexceedingxceeding tthathat ooff eevenven tthehe BBlacklack DeathDeath inin fourteenth-centuryfourteenth-century EEurope.urope. EEuropeansuropeans broughtbrought ddeadlyeadly vvirusesiruses aandnd bbacteria,acteria, suchsuch aass ssmallpox,mallpox, measles,measles, ttyphus,yphus, andand ccholera,holera, fforor wwhichhich NativeNative AmericansAmericans hadhad nono immunityimmunity (Denevan,(Denevan, 1976).1976). OOnn ttheirheir rreturneturn hhome,ome, EEuropeanuropean sailorssailors broughtbrought syphilissyphilis toto Europe.Europe. AlthoughAlthough lessless ddeadly,eadly, tthehe ddiseaseisease wwasas kknownnown ttoo hhaveave ccausedaused greatgreat socialsocial disruptiondisruption throughoutthroughout tthehe OldOld WWorldorld ((Sherman,Sherman, 22007).007). TThehe effectseffects ofof thethe ColumbianColumbian ExchangeExchange wwereere nnotot iisolatedsolated ttoo tthehe ppartsarts ooff tthehe wworldorld mmostost ddirectlyirectly pparticipatingarticipating inin tthehe eexchange:xchange: EEuropeurope aandnd tthehe AAmericas.mericas. IItt aalsolso hhadad large,large, althoughalthough llessess ddirect,irect, impactsimpacts onon AfricaAfrica andand Asia.Asia. EuropeanEuropean explorationexploration aandnd ccolonizationolonization ofof thethe vastvast ttropicalropical rregionsegions ofof thesethese continentscontinents waswas aidedaided byby thethe NNewew WWorldorld ddiscoveryiscovery ooff qquinine,uinine, tthehe fi rrstst eeffectiveffective treatmenttreatment forfor malaria.malaria. Moreover,Moreover, tthehe cultivationcultivation ofof fi nnanciallyancially lucrativelucrative cropscrops inin thethe Americas,Americas, alongalong withwith thethe devas-devas- ttationation ooff nnativeative ppopulationsopulations ffromrom ddisease,isease, rresultedesulted iinn a ddemandemand fforor llaborabor tthathat wwasas mmetet wwithith tthehe aabductionbduction andand forcedforced movementmovement ofof overover 1212 millionmillion AfricansAfricans duringduring tthehe ssixteenthixteenth toto nineteenthnineteenth centuriescenturies (Lovejoy,(Lovejoy, 22000;000; MManning,anning, 11990).990). TThehe ColumbianColumbian ExchangeExchange hhasas pprovidedrovided economistseconomists interestedinterested inin thethe long-long- ttermerm eeffectsffects ofof historyhistory onon economiceconomic developmentdevelopment withwith a richrich historicalhistorical llaboratory.aboratory. EEconomicconomic sstudiestudies hhaveave tthushus ffarar mmainlyainly ffocusedocused onon howhow EuropeanEuropean institutions,institutions, tthroughhrough colonialism,colonialism, werewere transplantedtransplanted toto non-Europeannon-European partsparts ofof thethe world.world. TThehe sseminaleminal ppapersapers bbyy EEngermanngerman aandnd SSokoloffokoloff ((1997),1997), LLaa Porta,Porta, Lopez-de-Silanes,Lopez-de-Silanes, SShleifer,hleifer, andand VishnyVishny ((1997,1997, 11998),998), aandnd AAcemoglu,cemoglu, JJohnson,ohnson, aandnd RRobinsonobinson (2001)(2001) eexaminexamine tthehe eeffectsffects thatthat EuropeanEuropean contact,contact, takingtaking thethe formform ofof formalformal andand informalinformal ccolonialolonial rule,rule, hadhad onon otherother societies.societies.1 IInn thisthis ppaper,aper, wewe attemptattempt toto broadenbroaden thethe scopescope ofof economiceconomic studiesstudies ofof thethe CColumbianolumbian EExchangexchange bbyy sstudyingtudying aaspectsspects ooff tthehe eexchangexchange tthathat hhaveave rreceivedeceived llessess aattention.ttention. FFirst,irst, wwee ppayay pparticulararticular aattentionttention ttoo tthehe eeffectsffects thatthat thethe exchangeexchange hadhad onon tthehe OldOld WWorld,orld, ratherrather thanthan examiningexamining ooutcomesutcomes iinn tthehe NNewew World.World. SSecond,econd, rratherather tthanhan cconcentratingoncentrating onon thethe effectseffects ofof thethe exchangeexchange thatthat workwork throughthrough institutionalinstitutional aandnd ppoliticalolitical structures,structures, wwee ffocusocus oonn tthehe lless-studied,ess-studied, butbut nono less-importantless-important chan-chan- nnels;els; namely,namely, thethe biologicalbiological exchangeexchange ofof foodfood ccropsrops aandnd disease.disease. OOurur hhopeope isis thatthat oourur bbroadroad ddescriptiveescriptive ooverviewverview ooff ssomeome ooff tthehe nneglectedeglected aaspectsspects ooff tthehe CColumbianolumbian EExchangexchange wwillill sspurpur furtherfurther more-rigorousmore-rigorous studiesstudies ooff tthehe llong-termong-term cconsequencesonsequences ooff tthesehese aaspectsspects ofof thethe exchange.exchange. WWee aarere awareaware ofof onlyonly a handfulhandful ofof empiricalempirical paperspapers thatthat eithereither focusfocus onon thethe eeffectffect ofof thethe exchangeexchange onon thethe OldOld WWorldorld oorr ffocusocus oonn cchannelshannels ootherther tthanhan llegalegal iinstitutions.nstitutions. AAcemoglu,cemoglu, JJohnson,ohnson, aandnd RRobinsonobinson ((2005)2005) eexaminexamine tthehe eeffectsffects ofof thethe tthree-cornerhree-corner AtlanticAtlantic tradetrade onon Europe.Europe. TheyThey argueargue tthathat tthehe pprofirofi ttss ffromrom tthehe ttraderade sstrengthenedtrengthened tthehe mmerchanterchant cclass,lass, whichwhich resultedresulted inin strongerstronger probusinessprobusiness institutionsinstitutions aandnd increasedincreased economiceconomic growth.growth. TwoTwo studiesstudies hhaveave rrecentlyecently exploredexplored thethe effectseffects fromfrom 1 Subsequent studies have since added to the understanding of the long-term effects of colonial rule and European contact on New World Societies. See for example Mitchener and McLean (2003),