Grossman和Helpman关于
diversity and trade,distribution of talent and trade, technology and trade 等的几篇重要和新近论文
By GENE M.GROSSMANAND GIOVANNI MAGGI*
Wedevelopacompetitivemodeloftradebetweencountrieswithsimilaraggregate
factorendowments.Thetradepatternreflectsdifferencesinthedistributionoftalent
acrossthelaborforcesofthetwocountries.Thecountrywitharelativelyhomo-
geneouspopulationexportsthegoodproducedbyatechnologywithcomplemen-
taritiesbetweentasks.Thecountrywithamorediverseworkforceexportsthegood
forwhichindividualsuccessismoreimportant.Imperfectobservabilityoftalent
strengthenstheforcesofcomparativeadvantage.Finally,weexaminetheeffectsof
tradeonincomedistributionandthecompositionoffirmsineachindustry. (JEL
F11,D51)
Alargefractionofworldtradetakesplace
betweencountrieswithsimilaraggregatefactor
endowmentsandsimilartechnologicalcapabil-
ities.Moreover,muchofthistradeinvolves
goodswithsimilarfactorintensities.Expla-
nationsforthesenow-familiarobservations
abound.Increasingreturnstoscalecanaccount
fortradeingoodsthataretechnologicallyalike
butdifferentiatedintheeyesofconsumers(e.g.,
PaulR.Krugman,1979).Oligopolisticcompe-
titioncanaccountfortwo-waytradeinidentical
productsundercertainassumptionsaboutoli-
gopolisticconduct(e.g.,JamesA.Brander,
1991).Smalltechnologicaldifferencesacross
countriescanaccountforhighvolumesoftrade
ingoodswithsimilarfactorintensitieswhen
factorendowmentratiosaresimilarandthere
aremoregoodsthanfactors(DonaldDavis,
1995).
Butalloftheseexplanationssharetheimpli-
cationthatthepatternoftradeisessentially
arbitrary.Iftradeismotivatedbyscaleecono-
mies,theorypredictsthenumberofvarieties
exportedbyeachcountry,butnotwhichones.If
tradereflectsoligopolisticcompetitionand
countrieshavesimilarcoststructures,onlythe
numbersofcompetitorsinthecountriesaffect
theirmarketshares,andthesenumbersarenot
explainedbythemodels.Iftradeisgenerated
bysmalltechnologicaldifferences,thepattern
ofsuchdifferencesinevitablywillbedifficultto
predict.
Yetitseemsthattherearesystematicdiffer-
encesinthetradingpatternsof,say,theUnited
StatesandJapan,orGermanyandItaly.Japan
tendstoexcelinindustriesrequiringcareand
precisioninalongsequenceofproduction
stages.Itsexportsincludemanysophisticated
consumergoods,suchasautomobilesandhigh-
endconsumerelectronics.WhereastheUnited
Statesexportsmanygoodsandserviceswhose
valuereflectsdisproportionatelytheinputofa
fewverytalentedindividuals.Itshighlysuc-
cessfulsoftwareindustryisanexampleofthis.
Sotooaresomeofthefinancialservicesema-
natingfromWallStreet.SimilartoJapan,Ger-
many’scomparativeadvantageresidesinits
manufacturingsector;itexportspassengercars,
industrialequipment,andchemicals.Again,
qualitycontrolplaysalargepartinexplaining
itssuccessinthesesectors.ForItaly,likethe
UnitedStates,internationalcompetitivenessof-
tenreflectstheoutstandingperformanceofone orafewpersons.Italyisknown,forexample,
foritsinnovativefurniturestyles,itsfashion
designs,anditsmovies.