Network Structure, Self-Organization and the Growt

Version24June04NetworkStructure,Self-OrganizationandtheGrowthofInternationalCollaborationinScienceCarolineS.Wagner*andLoetLeydesdorffAmsterdamSchoolofCommunicationsResearch(ASCoR)UniversityofAmsterdamAbstractUsingdatafromco-authorshipsattheinternationallevelinallfieldsofsciencein1990and2000,andwithinsixcasestudiesatthesub-fieldlevelin2000,differentexplanationsforthegrowthofinternationalcollaborationinscienceandtechnologyareexplored.Wefindthatfewoftheexplanationswithintheliteraturecanbesupportedbyadetailedreviewofthedata.Toenablefurtherexplorationoftheroleofrecognitionandrewardsasorderingmechanismswithinthesystem,weapplynewtoolsemergingfromnetworkscience.Theseenquiriesshowsthatthegrowthofinternationalco-authorshipscanbeattributedtoself-organizingphenomenonbasedonpreferentialattachment(searchingforrecognitionandreward)withinnetworksofco-authors.Theco-authorshiplinkscanbeconsideredasacomplexnetworkwithsub-dynamicsinvolvingfeaturesofbothcompetitionandcooperation.Theanalysissuggeststhatthegrowthofinternationalcollaborationismorelikelytoemergefromdynamicsatthesub-fieldleveloperatinginallfieldsofscience,albeitunderinstitutionalconstraints.Implicationsforthemanagementofglobalscientificcollaborationsareexplored.Keyword:scientificcollaboration;socialnetworkanalysis;sciencepolicy;socialsystems;preferentialattachment1.IntroductionIntheliteratureonthegrowthofcollaborationinscienceandtechnology,theinfluenceoftherewardssystemoncollaborationattheinternationallevelhasnotreceivedagreatdealofattention.(Whitley1984)Manystudieshavedemonstratedthegrowthofinternationalcollaborationinscience(ICS)byusingco-authorships.(Narin1991;Luukkonenetal.1992and1993;Miquel&Okubo1994;Doréetal.1996;Georghiou1998;Glänzel2001).Perssonetal.(forthcoming)showthatcitationstoarticlesresultingfrominternationalcollaborationshavegrownfasterthanthosereferring*Correspondenceto:C.S.Wagner,ASCoR,Kloveniersburgwal48Amsterdam1012DXNetherlands,[e-mail].(1991)hasshownthatinternationallyco-authoredarticlesaremorehighlycitedthanotherarticles.Despitethisbodyofevidence,thequestionofwhythisclassofresearchisgrowingsoquicklyorwhyithasarelativelyhighimpactneedsmorediscussion.Atheoreticallysatisfyingexplanationofthephenomenonhasyettobeoffered.(Katz&Hicks1987;Wagner-Döbler2001)Thisarticlecontinuestheseinquiriesalongtwolines.Drawingupondata(publishedelsewhere)for1990and2000,differentexplanationsofferedwithintheliteraturefortheincreaseininternationalcollaborationarediscussed.WefindthatexistingexplanationsareincapableoffullyexplainingtheemergingstructureofICS.Inseekingotherexplanations,weturntorecentliteraturefromthenetworksciences.Physicistsneedinglargedatasetsforthestudyofnetworkdynamicshaveusedscientificco-authorshipsasasubject.Intheprocess,theyhaverevealedfascinatingdynamicsaboutcollaborativenetworks,includingthemechanismofpreferentialattachmentasastructuringfactor.UsingthetoolsdevelopedbyBarabási&Albert(1999)andNewman(2001)weinvestigatewhetherthesemechanismsalsoapplyattheinternationallevel.Ourfindingsrevealtheemergingstructureoflinkageswithintheinternationalsystematthesub-fieldlevel,andperhapsmovesciencestudiesclosertowardsatheoreticallysatisfyingexplanationfortheriseofinternationalcollaboration.2.AbriefreviewoftheliteratureexaminingtheriseofinternationalcollaborationOverthepast25years,anumberofreasonshavebeensuggestedtoexplainthegrowthofICS.Onegroupconsiderstheenvironmentwithinwhichscienceoperates:theenvironmentalfactorscanbedividedintointernalandexternalfactors.Asecondgroupconsiderstheconnectionswithinandaroundscience,andthesecanbedividedintothoserelatedtothegrowthofcapacitytoconductscience(morescientistsinmorecountriesareavailabletocooperate),andthoseexaminingtheincreasinginterconnectednessofscientists(withinandacrosscountriesduetotransdisciplinarityandtheriseoftheinformationsociety).Table1cross-referencesthesefactors,andwithintheresultingcells,thetableshowscitationstorelevantideasfromtheliterature.2Version24June04Historicalrelationshipsrelatestogeographicproximityorcolonialties(Zittetal.2000)Increaseininternationaltrade(Ben-David1971);Growthofinformationandcommunicationstechnologies(Gibbonsetal.1994;StarrInternaldisciplinarydifferentiationofscience(Stichweh1996);Field-specificcharacteristicsofmegascience(Galison&Helvy1992);Professionalisationofscientificinstitutes(Beaver&Rosen1978)RelatingtotheinterconnectednessofscientistsRisinginvestmentsbynationsanddonorsincreasingS&Tcapacity(Wagneretal2001)Center-peripherytheoryoflaggingcountriesseekingtocooperatewithleadingones(Schott1998;Shils1983;Ben-David1971)RelatingtothediffusionofscientificcapacityExternaltoscienceInternaltoscienceHistoricalrelationshipsrelatestogeographicproximityorcolonialties(Zittetal.2000)Increaseininternationaltrade(Ben-David1971);Growthofinformationandcommunicationstechnologies(Gibbonsetal.1994;StarrInternaldisciplinarydifferentiationofscience(Stichweh1996);Field-specificcharacteristicsofmegascience(Galison&Helvy1992);Professionalisationofsci