Does Going Public Affect Innovation
更新时间:2024-04-12 09:30:01 阅读量: 综合文库 文档下载
- does推荐度:
- 相关推荐
Accepted ArticleDoesGoingPublicA?ectInnovation?
SHAIBERNSTEIN?
ABSTRACT
Thispaperinvestigatesthee?ectsofgoingpubliconinnovationbycomparingtheinnovationactivityof?rmsthatgopublicwith?rmsthatwithdrawtheirIPO?lingandremainprivate.NASDAQ?uctuationsduringthebook-buildingphaseareusedasaninstrumentforIPOcompletion.Usingpatent-basedmetrics,I?ndthatthequalityofinternalinnovationdeclinesfollowingtheIPO,and?rmsexperiencebothanexodusofskilledinventorsandadeclineintheproductivityoftheremaininginventors.However,public?rmsattractnewhumancapitalandacquireexternalinnovation.Theanalysisrevealsthatgoingpublicchanges?rms’strategiesinpursuinginnovation.
StanfordUniversity.IamdeeplygratefultoFritzFoley,JoshLerner,AndreiShleifer,andJeremySteinfortheirinvaluablecomments.IalsothankPhilippeAghion,E?Benmelech,LauraField,PaulGompers,RobinGreenwood,SamHanson,OliverHart,VictoriaIvashina,DirkJenter,BillKerr,JacobLeshno,GustavoManso,RamanaNanda,FranciscoPerez-Gonzalez,DavidScharfstein,AntoinetteSchoar,AmitSeru,AdiSunderam,RickTownsend,andJe?Zwiebelforhelpfulcomments.IamgratefultoseminarparticipantsatChicagoUniversity,ColumbiaUniversity,DartmouthCollege,EntrepreneurialFinanceandInnovationConference,HarvardBusinessSchool,HebrewUniversity,LondonBusinessSchool,LondonSchoolofEconomics,NBERProductivityLunch,NorthwesternUniversity,SearleConferenceonInnovationandEntrepreneurship,StanfordUniversity,Tel-AvivUniversity,UniversityofBritishColumbia,andUniversityofPennsylvaniaforhelpfulcommentsandsuggestions.AndrewSpeenprovidedsuperbresearchassistance.IamgratefulforfundingfromtheEwingMarionKau?manFoundation.
?
This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/jofi.12275.
This article is protected by copyright. All rights reserved.
Doesthetransitiontopublicequitymarketsa?ectinnovation?Thisquestionisimportantgiventhecriticalroleofinnovationinpromotingeconomicgrowth(Solow(1957))andtheprevalenceoftechnological?rmsintheinitialpublico?ering(IPO)marketoverrecentyears.1Althoughalargebodyofresearchexaminestheperformanceof?rmsaroundtheirIPO,littleisknownaboutthee?ectsofgoingpubliconinnovation.Thispaper’smaincontributionistoshowthatgoingpublica?ectsthreeimportantdimensionsofinnovationactivity:thecreationofinternallygeneratedinnovation,theproductivityandmobilityofindividualinventors,andtheacquisitionofexternalinnovation.
Theoretically,infrictionless?nancialmarkets,sellingequitiespubliclyshouldhaveno
Accepted Articlebearingonsubsequentinnovationactivity.Under?nancialfrictions,however,thetransitiontopublicequitymarketsimproves?rms’accesstocapital,whichcanleadtoanincreaseininnovationactivity,becausesuchactivityisparticularlylikelytobesensitiveto?nancingconstraints(Arrow(1962),HallandLerner(2010)).Ontheotherhand,agencyproblemsassociatedwiththetransitiontopublicequitymarketsmayundermine?rmincentivestoinnovate(BerleandMeans(1932),JensenandMeckling(1976)).
Ultimately,empiricalinvestigationisnecessarytodisentanglethepositiveandadverse
e?ectsofpubliclistingoninnovation.Estimatingthesee?ects,however,ischallengingduetoaninherentselectionbiasassociatedwiththedecisiontogopublic.Astandardapproachtostudyingthedynamicsof?rmoutcomesaroundtheIPOistousewithin-?rmvariation.ButasJainandKini(1994)note,?rmschoosetogopublicataspeci?cstageintheirlifecycle,andasaresultthisapproachmayproducebiasedestimatesoftheIPOe?ect.Forinstance,if?rmschoosetogopublicfollowinganinnovationbreakthrough,asarguedbyP′astor,Taylor,andVeronesi(2009),2thenpost-IPOperformancemayre?ectreversiontothemeanandtherebymixlifecyclee?ectswiththeIPOe?ect.
ToovercomethisselectionbiasandestimatetheIPOe?ectoninnovation,Iconstruct
asampleofinnovative?rmsthat?leaninitialregistrationstatementwiththeSecuritiesandExchangeCommission(SEC)inanattempttogopublic,andtheneithercompleteor
1
This article is protected by copyright. All rights reserved.
withdrawtheir?ling.Combinedwithstandardpatent-basedmetrics,thissampleallowsmetocomparetheinnovationactivityof?rmsthatgopublicwiththatofprivate?rmsthatintendedtogopublicandhenceareatasimilarstageintheirlifecycle.Ofcourse,comparingcompleteandwithdrawnIPO?lingsintroducesanewbiasassociatedwiththedecisionof?rmstowithdrawtheIPO?lingandremainprivate.
Toaddressthisconcern,IuseNASDAQ?uctuationsoverthetwomonthsfollowingthe
Accepted ArticleIPO?lingdateasaninstrumentforIPOcompletion,relyingon?lers’sensitivitytoaggregatestockmarketmovementsduringthebook-buildingphase.Consistentwithpriorliterature,I?ndthattheseshort-runNASDAQ?uctuationsstronglypredictIPOcompletion,withthee?ectconcentratedatmarketdeclines(e.g.,Benvenisteetal.(2003),Busaba,BenvenisteandGuo(2001)).Intheanalysis,theIPOe?ectisidenti?edfromdi?erencesinlong-runinnovation(i.e.,innovationover?ve-yearperiod)between?rmsthat?letogopublicinthesameyearbutexperiencedi?erentpost-?lingNASDAQreturns.
Fortheinstrumenttobevalid,itneedstosatisfytheexclusionrestrictioncondition,
thatis,two-monthNASDAQreturnsmustberelatedtothelong-runinnovationmeasuresonlythroughtheIPOcompletionchoice.I?ndempiricalsupportforthevalidityoftheinstrument(seeSectionII.Cforadetaileddiscussion).Whilereduced-formanalysisshowsthattheinstrumentsigni?cantlyexplainslong-runinnovation,itmayalsoa?ectinnovationthroughotherchannels.Totheextentthatthisisthecase,two-monthNASDAQreturnsshouldalsoexplainlong-runinnovationoutsidethebook-buildingphase.Aplacebotestrevealsthatoutsidethebook-buildingphase,whenownershipchoiceis?xed,NASDAQreturnshavenoe?ectonlong-runinnovation.This?ndingisconsistentwiththenotionthatshort-termNASDAQreturnsduringthebook-buildingphasea?ectlong-runinnovationonlythroughtheIPOcompletionchoice.
Usingtheinstrumentalvariablesapproach,I?ndasigni?cantlinkbetweenpublicowner-
shipandinnovation:goingpubliccausesasubstantial40Tclineininnovationnoveltyasmeasuredbypatentcitations.Atthesametime,I?ndnochangeinthescaleofinnovation,
2
This article is protected by copyright. All rights reserved.
asmeasuredbythenumberofpatents.Theseresultssuggestthatthetransitiontopublicequitymarketsleads?rmstorepositiontheirR&Dinvestmentstowardmoreconventionalprojects.
Havingshownthatgoingpublica?ectsthecompositionofinnovativerelativetoconven-
Accepted Articletionalprojects,Istudythee?ectsofgoingpubliconindividualinventors’productivityandmobilityovertime.I?ndthatthequalityofinnovationproducedbyinventorswhoremainatthe?rmdeclinesfollowingtheIPO,andkeyinventorsaremorelikelytoleave.The?rmsthatgopublicarealsomorelikelytogeneratespin-o?companies,suggestingthatinventorswholeaveremainentrepreneurial.Thesee?ectsarepartiallymitigatedbytheabilityofpublic?rmstoattractnewinventors.
Ialso?ndastarkincreaseinthelikelihoodthatnewlypublic?rmsacquirecompanies
intheyearsfollowinganIPO.Tobetterunderstandwhethertheseacquisitionsareusedtopurchasenewtechnologies,Icollectinformationontargets’patentportfolios.I?ndthatpublic?rmsacquireasubstantialnumberofpatentsthroughM&A:acquiredpatentsconstitutealmostathirdof?rms’totalpatentportfoliointhe?veyearsfollowingtheIPO.TheacquiredpatentsareofhigherqualitythanthepatentsproducedinternallyfollowingtheIPO.
Theseresultssuggestthatthetransitiontopublicequitymarketsa?ectsthestrategies
that?rmsemployinpursuinginnovation.Whilepubliclytraded?rmsgeneratemoreincre-mentalinnovationinternally,theyalsorelymoreheavilyonacquiringtechnologiesexternally.ThisshifttakesplaceconcurrentwithasubstantialinventorturnoveraftertheIPO.Whatleadstothesechanges?Astockmarketlistingmayincreasethescopeforagency
problems,leading?rmstopursuelessinnovationfollowingtheIPO(BerleandMeans(1932),JensenandMeckling(1976)).Alternatively,agencyproblemsmaybeconcentratedinprivate?rmsthatpursuetoomuchinnovation.Finally,itmaybethecasethattheresultsarenotdrivenbyagencyproblems,butrathertheimprovedaccesstocapitalallows?rmstofocusoncommercializationaftertheIPO.Suchastrategyisnotviablefor?rmsthatremainprivate
3
This article is protected by copyright. All rights reserved.
andthereforefocusoninnovationonly.IdiscussthesehypothesesindetailinSectionIV.I?ndsupportiveevidenceformanagerialcareerconcerns,consistentwithrecentpapersonagencyproblemsinpublicequitymarkets(e.g.,Aghion,VanReenen,andZingales(2013),Asker,Farre-Mensa,andLjungqvist(2014),Fismanetal.(2013),andGao,Hsu,andLi(2014)).
Thepaperisrelatedtoseveralstrandsoftheliterature.First,byproposinganidenti?-
Accepted ArticlecationstrategytoisolatetheIPOe?ect,andfocusingon?rms’innovationactivitiesaroundtheIPO,thispapercontributestotheIPOliteraturethatexplores?rmbehaviorfollowingtheIPOanddocumentsadeclinein?rmperformancemeasuressuchaspro?tabilityandproductivity(Chemmanur,He,andNandy(2010),DegeorgeandZeckhauser,(1993),JainandKini(1994),Mikkelson,Partch,andShah(1997),Pagano,Panetta,andZingales(1996,1998),andP′astor,Taylor,andVeronesi(2009)).3
Second,byfocusingontheex-postconsequencesofbecomingapubliclytraded?rm
oninnovation,andillustratingacomplextrade-o?betweenpublicandprivateownershipstructures,thepapercontributestoagrowingbodyofworkthatcomparesthebehaviorofpublicandprivate?rmsalongvariousdimensions,suchasinvestmentsensitivity(e.g.,Asker,Farre-Mensa,andLjungqvist(2014),Sheen(2009)),debt?nancingandborrowingcosts(SaundersandSte?en(2011),Brav(2009)),dividendpayouts(MichaelyandRoberts(2012)),andCEOturnover(Gao,Harford,andLi(2014)).
Thisworkalsocontributestoagrowingliteraturethatexplorestheroleofgovernance,
capitalstructure,andownershiponcorporateinnovation.Forexample,Seru(2014)exploresthee?ectsofmergersandacquisitionsoninnovation,Lerner,Sorensen,andStromberg(2011)examinetheimpactofprivateequityinvestments,andAghion,VanReenen,andZingales(2013)exploretheimportanceofinstitutionalinvestorsandconcentratedownership.Inaddition,thispaperisconnectedtothetheoreticalliteratureontheorganizationofR&D(e.g.,AghionandTirole(1994)),andmorebroadlytoempiricalworkontheboundariesofthe?rm(e.g.,Robinson(2008),Beshears(2013),andSeru(2014)).
4
This article is protected by copyright. All rights reserved.
Therestofthepaperproceedsasfollows.SectionIdescribesthedataandpresentssummarystatisticsandSectionIIpresentstheempiricalstrategy.SectionIIIprovidesthemainresultsandSectionIVdiscussespotentialchannels.SectionVconcludes.
Accepted ArticleI.Data
ThedatainthisanalysiscompriseinformationonIPO?lings,patents,hand-collected
?nancialinformation,andinformationonother?rmcharacteristics.
A.IPOFilings
ToapplyforanIPO,a?rmisrequiredtosubmitaninitialregistrationstatementtothe
SEC(usuallyFormS-1),whichcontainstheIPO?ler’sbusinessand?nancialinformation.FollowingthesubmissionoftheFormS-1,?lersmarkettheequityissuancetoinvestors(thebook-buildingphase)andhavetheoptiontowithdrawtheIPO?lingbysubmittingFormRW.WithdrawalsarecommoninIPOmarkets,withapproximately20%ofallIPO?lingsultimatelywithdrawn.
IcollectallIPO?lingsusingThomsonFinancial’sSDCNewIssuesdatabase.Thesample
startsin1985,whenSDCbegancoveringwithdrawnIPOssystematically,andendsin2003,astheanalysisexplorestheinnovationoutcomesof?rmsinthe?veyearsaftertheIPO?ling.FollowingtheIPOliterature,IexcludeIPO?lingsof?nancial?rms(SICbetween6000and6999),unito?ers,closed-endfunds(includingREITs),ADRs,limitedpartnerships,specialacquisitionvehicles,andspin-o?s.Iidentify5,583completeIPOsand1,599withdrawnIPO?lingsfrom1985to2003.
5
This article is protected by copyright. All rights reserved.
B.PatentData
B.1.
MeasuringInnovativeActivity
Accepted ArticleAnextensiveliteratureontheeconomicsoftechnologicalchangedemonstratesthat
patentingactivityre?ectsthequalityandextentof?rminnovation,andtheuseofpatentingactivityasameasureofinnovationiswidelyaccepted(Hall,Ja?e,andTrajtenberg(2001),Lanjouw,Pakes,andPutnam(1998)).Importantlyforthisanalysis,patentinformationisavailableforbothpublicandprivate?rms,unlikeR&Dexpenditures,andallowstomeasure?rminnovationoutputalongseveraldimensions.
Themostbasicmeasureofinnovationoutputisasimplecountofthenumberofpatents
granted.However,patentcountscannotdistinguishbetweenbreakthroughinnovationandincrementaldiscoveries(e.g.,Griliches(1990)).Asecondmetricthereforere?ectsthenoveltyofapatentbycountingthenumberofcitationsapatentreceivesfollowingitsapproval.Thenumberofpatentcitationsalsocapturestheeconomicimportanceoftheinnovation,asitcorrelateswitha?rm’smarketvalue(Hall,Ja?e,andTrajtenberg(2005)).Indeed,Koganetal.(2012)showthatthestockmarketstrongly,andpositivelyreactstotheapprovalofpatentsthatareeventuallyhighlycited,andthatsuchpatentspredictboth?rmproductivityandcapitalandlabor?owsfromnon-innovativetoinnovative?rmswithintheindustry.Bothcitationratesandpatentcountsvaryovertimeandacrosstechnologies.Variation
maystemfromchangesintheimportanceoftechnologiesorfromchangesinthepatentsystem.Therefore,acomparisonofrawpatentsandcitationsisonlypartiallyinformative.Toadjustpatentcitations,IfollowHall,Ja?e,andTrajtenberg(2001)andconstructScaled
Citationsbyscalingeachpatentcitationcountbytheaveragenumberofcitationsofmatchedpatents,wherematchedpatentsarepatentsgrantedinthesameyearandinthesametechnologyclass.Similarly,toadjustpatentcounts,Iweighteachpatentbytheaveragenumberofpatentsgrantedby?rmsinthesameyearandtechnologyclass.Hence,patentsgrantedintechnologiesinwhich?rmsissuemorepatentsreceivelessweight.TheScaled
6
This article is protected by copyright. All rights reserved.
NumberofPatentsisasimplesumofthescaledpatentsa?rmgeneratesinayear.AsadditionalmeasuresIemployOriginalityandGenerality,whichusethedistributionofcitationstocapturethefundamentalnatureofinnovation(Trajtenberg,Henderson,andJa?e(1997)).Apatentthatcitesabroaderarrayoftechnologyclassesisviewedashavinggreateroriginality,whileapatentthatiscitedbyamoretechnologicallyvariedarrayofpatentsisviewedashavinggreatergenerality.4Similarlytopatentcountsandcitations,ScaledOriginalityandScaledGeneralityarenormalizedbythecorrespondingaverageoriginalityorgeneralityofallpatentsgrantedinthesameyearandtechnologyclass.
B.2.PatentDataSources
ThepatentdatacomefromtheNationalBureauofEconomicResearch(NBER)patent
Accepted Articledatabase,whichincludesdetailedinformationonmorethanthreemillionpatentssubmittedtotheU.S.PatentandTrademarkO?ce(USPTO)from1976to2006(Hall,Ja?e,andTrajtenberg(2001)).
IusetheNBERbridge?letoCOMPUSTATtomatchpatentsto?rmsthatcompleted
theIPO?ling,andmanuallymatchpatentstowithdrawnIPO?lings.5Irestrictthesampleto?rmswithatleastonesuccessfulpatentapplicationovertheperiodfromthreeyearsbeforeto?veyearsaftertheIPO?ling.Thisyields1,488innovative?rmsthatwentpublicand323thatwithdrewtheIPOapplication.
Thegoalistocollectinformationon?rms’innovationactivityinthe?veyearsafterthe
IPO?lingregardlessofwhetherthe?rmsareacquiredorgopublicinasecondattempt,toavoidbiasesthatmayarisefromtruncating?rmactivity.Afterall,?rmexitsareyetanotherconsequenceoftheIPOe?ectthatin?uences?rms’innovationpaths.Collectingpatentinformationsubsequentto?rmexitsisfeasibleasinmostcases,evenifa?rmisacquired,itspatentsarestillassignedtotheacquiredratherthantheacquiringcompany.6
Icalculatethenumberofcitationsapatentreceivesinthecalendaryearofitsapprovalandinthesubsequentthreeyears.Thistimeframeisselectedto?tthenatureofthesample.
7
This article is protected by copyright. All rights reserved.
SincemanyoftheIPO?lingsinthesampleoccurtowardtheendofthe1990s,increasingthetimehorizonofcitationcountswouldreducesamplesize.Furthermotivatingtheselectedcitationhorizonisthefactthatcitationsareconcentratedinthe?rstfewyearsfollowingapatent’sapproval,withaconsiderableserialcorrelationincitationrates(AkcigitandKerr(2013)).
SincetheNBERpatentdatabaseendsin2006,Isupplementitwithinformationfrom
Accepted ArticletheHarvardBusinessSchool(HBS)patentdatabase,whichcoverspatentsgrantedthroughDecember2009.Thisenablescalculationofcitationsforpatentsgrantedtowardtheendofthesample.Overall,thesampleconsistsof39,306grantedpatentsof?rmsthatwentpublicand4,835grantedpatentsof?rmsthatwithdrewtheir?ling.[INSERTTABLEI]
TableIcomparesthepatentingactivityofwithdrawnandIPO?rmsinthethreeyears
priortotheIPO?ling.I?ndnosigni?cantdi?erencesacrossanyofthepatentingmeasures.SinceavalueofoneforScaledCitationsimpliesthata?rmisproducingpatentsofaveragequality,itisinterestingtonotethatbothIPO?rmsandwithdrawn?rmsproducepatentsthataresubstantiallymorecitedthancomparablepatentsintheyearsprecedingtheIPO?ling(80%higherforwithdrawn?rmsand89%higherforIPO?rms).Thisevidencesuggeststhat?rmsthatchoosetogopublicarelikelytodosofollowinginnovationbreakthroughs,raisingconcernsofpost-IPOmeanreversion,regardlessoftheIPOe?ect.Thisfurthermotivatestheempiricalapproachinthispaper.7
C.FinancialInformationandFirmCharacteristics
Theanalysisofprivate?rmsiscomplicatedduetodatalimitations.Whilepatentsare
usefulincapturingtheinnovationactivityofbothpublicandprivate?rms,no?nancialinformationisreadilyavailableforwithdrawn?rmsinstandard?nancialdatabases.Toovercomethisconstraint,Icollectwithdrawn?rms’?nancialinformationfrominitialregis-8
This article is protected by copyright. All rights reserved.
trationstatementsbydownloadingFormS-1?lingsfromtheSEC’sEDGARdatabase,whichisavailableasof1996.Icollect?nancialinformationforIPO?rmsfromCOMPUSTATandCapitalIQ.
Additionalinformationon?rmcharacteristicscomesfromvarioussources.Iobtaindata
Accepted Articleonventurecapital(VC)fundingfromSDC,VentureXpert,andregistrationstatements.Isupplementthesedatawithinformationona?rm’sageatthetimeoftheIPO?linganditsunderwriters’rankingfromregistrationforms,VentureXpert,JayRitter’swebpage,andtheSDCdatabase.Finally,Icollectinformationon?rmexits,thatis,eventsinwhicha?rmisacquired,goespublicinasecondattempt(forwithdrawn?rms),or?lesforbankruptcy.IuseCOMPUSTATandCapitalIQtosearchforacquisitionsandbankruptcies,andtheSDCdatabasetoidentifysecondIPOsofwithdrawn?rms.Iperformextensivecheckstoverifythenatureofprivate?rms’exitsusingtheDealPipelinedatabase,Lexis-Nexisandwebsearches.
TableIcomparesthecharacteristicsofIPO?rmsandwithdrawn?rmsatthetimeof
?ling.I?ndnosigni?cantdi?erencesin?rmsize,measuredbythelogof?rmassets,orinR&Dexpendituresnormalizedby?rmassets.However,withdrawn?rmshaveahighercash-to-assetsratioandlowernetincometoassets.Ialso?ndnosigni?cantdi?erencesinthereputationoftheleadunderwriter,whichisoftenusedasaproxyfor?rmquality(CarterandManaster(1990),Carter,Dark,andSingh(1998),andLoughranandRitter(2004)),orin?rmageatthetimeof?ling.
Therearestarkdi?erences,however,intheNASDAQ?uctuationsthat?rmsexperience
aftertheIPO?ling.Speci?cally,?rmsthatgopublicexperienceonaveragea3%increaseintwo-monthNASDAQreturnsfollowingtheIPO?ling,while?rmsthatwithdrawexperienceonaverageasharpdropof6%overasimilarperiod.Thedi?erencesinNASDAQreturnsinthethreemonthspriortotheIPO?ling,however,arefairlysmall(5%increasefor?rmsthatultimatelyremaineprivateversus7%forthosethatgopublic).Thesedi?erencesprovidefurthermotivationforusingNASDAQ?uctuationsasasourceofvariationthata?ectsIPO
9
This article is protected by copyright. All rights reserved.
completionchoices.Idiscussthisindetailinthenextsection.
TableIalsosummarizes?rmexitsinthe?veyearsfollowingtheIPO?ling.I?ndthat29%ofthewithdrawn?rmsand24%oftheIPO?rmsareacquiredoverthisperiod,withthedi?erencebetweenthetwogroupsinsigni?cant.Only2%ofbothIPOandwithdrawn?rmsgobankrupt.Additionally,18%ofthewithdrawn?rmsultimatelygopublicinasecondattemptinthe?veyearsfollowingtheIPO?ling.
Thesmallfractionofwithdrawn?rmsthatreturntopublicequitymarketsinasecond
Accepted Articleattemptishighlightedintheliterature(DunbarandFoerster(2008),Busaba,Beneviste,andGuo(2001)).SeveralexplanationsexistforthelowfractionofsecondattemptIPOs.ReturningtoIPOmarketsinasecondattemptmaybedi?cultasthewindowofopportunitymayhaveclosedduetotheboomandbustnatureofIPOmarkets(IbbotsonandRitter(1995)).BrauandFawcett(2006)?ndthatthemostimportantsignalwhengoingpublicisa?rm’spasthistoricalearnings.Ifgoingpublicrequiresseveralyearsoffastgrowthtoattractinvestors’attention,suchgrowthmaybedi?culttoreplicateinasecondattempt.DunbarandFoerster(2008)furthersuggestthattherearereputationalcostsassociatedwiththedecisiontowithdraw,whichmayprevent?rmsfromreturningtoequitymarkets.
II.EmpiricalStrategy
A.EmpiricalDesign
Identifyingthee?ectsofgoingpubliconinnovationand?rmoutcomesischallengingdue
toinherentselectionissuesthatarisefromthedecisiontogopublic.ThisconcernisevidentinFigure1,whichpresentswithin-?rmchangesininnovationquality,asmeasuredbyScaledCitations,intheyearsaroundtheIPO.8FirmsexperienceamonotonicdeclineinpatentnoveltybetweenthetwoyearsbeforetheIPOeventandthe?veyearsafter.Duetothechoicetogopublic,post-IPOperformancecouldbedrivenbyreversiontothemeanandlifecyclee?ects,ratherthanthee?ectofbecomingapubliclytraded?rm.
10
This article is protected by copyright. All rights reserved.
[INSERTFIGURE1]
Whatisareasonablecounterfactualfor?rmsthatgopublic?Simplycomparingpost-IPOinnovationtoanaverageprivate?rmmaygeneratebiasedestimates,asmostprivatecompaniesarefundamentallydi?erentandnevergopublic.ThisisevidentinTableI,whereonecanseethatpre-?linginnovationqualityof?rmsthatgopublicis80%higherthantheaverageinnovationintherespectivetechnologicalclasses.Toovercomethisconcern,Ifocusonthose?rmsthatsubmitaninitialregistrationstatementtotheSECinanattempttogopublic.
Icomparethelong-runinnovationof?rmsthatgopublicwith?rmsthat?ledtogopublic
Accepted Articleinthesameyearbutultimatelywithdrawtheir?lingandremainedprivate.Thissetupisattractiveasitallowsforcomparisonofthepost-IPOperformanceof?rmsthatgopublicwiththatofprivate?rmsatasimilarstageintheirlifecycle.Thebaselinespeci?cationis
Yipost=α1+β1IPOi+γ1Yipre+Xi??δ1+νk+μt+ε1i,
(1)
whereYipostistheaverageinnovationperformanceinthe?veyearsfollowingtheIPO?ling
(averagescaledcitations,averagescaledoriginality/generality,andaveragescalednumberofpatentsperyear),YipreistheequivalentmeasureinthethreeyearspriortotheIPO?ling,andIPOiisthedummyvariableofinterest,indicatingwhethera?lergoespublicorremains
private.Underthenullhypothesisthatgoingpublichasnoe?ectoninnovation,β1should
notbestatisticallydi?erentfromzero.Thismodelincludesindustry(vk)andIPO?ling
year(μt)?xede?ects.
IfthedecisiontowithdrawanIPO?lingisrelatedtounobservedinnovationpolicyor
innovativeopportunities(capturedintheerrorterm),thenβ1maybebiased.Therefore,IinstrumentfortheIPOcompletionchoiceusingNASDAQreturnsinthe?rsttwomonthsofthebook-buildingphase.Thedecisiontouseatwo-monthwindowissomewhatarbitrary.OnecouldusetheNASDAQreturnsovertheentireperiodofthebook-buildingphase.
11
This article is protected by copyright. All rights reserved.
However,sincethelengthofthebook-buildingphaseisoftencorrelatedwiththelikelihoodofwithdrawing,Ichoosea?xedwindowthatissu?cientlyshorterthantheaveragelengthofthebook-buildingperiod.
The?gurebelowillustratesthetimelineoftheIPO?lingandtheNASDAQ?uctuations
Accepted Articleduringthebook-buildingphase.Onaverage,theownershipchoiceismadewithinthefourmonthsfollowingtheIPO?ling.Firm-levelinnovationismeasuredoverthe?ve-yearperiodaftertheIPO?ling.9
Toimplementtheinstrumentalvariablesapproach,Iestimatethefollowing?rst-stage
regression:
IPOi=α2+β2NSDQi+γ2Yipre+Xi??δ2+νk+μt+ε2i,
(2)
whereNSDQiistheinstrumentalvariable.Thesecond-stageequationestimatestheimpactofIPOoninnovationactivity:
??Yipost=α3+β3IPOi+γ3Yipre+Xi??δ3+νk+μt+ε3i,
(3)
??whereIPOiarethepredictedvaluesfrom(2).Iftheconditionsforavalidinstrumentalvariablearemet,β3capturesthecausale?ectofanIPOoninnovationoutcomes.Iimplementtheinstrumentalvariableestimatorusingtwo-stageleastsquares(2SLS).Ialsouseaquasi-maximumlikelihood(QML)Poissonmodeltoestimatethespeci?cation(BlundellandPowell(2004)),whichisthestandardestimationmethodusedinboththeinnovationliteratureandcountdataanalysismoregenerally.
Itisimportanttonotethattheestimatesintheinstrumentalvariablesanalysisare
12
This article is protected by copyright. All rights reserved.
comingonlyfromthesensitive?rms(ImbensandAngrist(1994)).Inotherwords,theestimatesarecomingonlyfromthose?rmsthatwouldaltertheirIPOcompletiondecisioniftheyexperienceaNASDAQdrop,andthereforearesensitivetochangesintheinstrument.IntheInternetAppendixIprovideasimpleexampletoillustratethispoint.InthenextsectionIdiscusstheassumptionsthatneedtoholdfortheinstrumenttobevalid.
Accepted ArticleB.NASDAQFluctuationsandIPOCompletion
Fortheinstrumenttobevalid,itmuststronglya?ectIPOcompletionchoice.Indeed,
issuersarehighlysensitivetostockmarket?uctuationsduringthebook-buildingphase(Benvenisteetal.(2003),Busaba,Benveniste,andGuo(2001),Dunbar(1998),DunbarandFoerster(2008),EdelenandKadlec(2005)).ThissensitivityisalsoillustratedinFigure2,whichplotsthefractionofmonthly?lingsthatultimatelywithdrawagainstthetwomonthsofNASDAQreturnscalculatedfromthemiddleofeachmonth,whichapproximatesthestockmarket?uctuationsduringtheinitialpartofthebook-buildingphase(thecorrelationofthetwoplotsequals-0.44andissigni?cantlydi?erentfromzeroatthe1%level).Consistentwiththisevidence,asurveybyBrauandFawcett(2006)?ndsthatCFOsthatwithdrawanIPOregistrationindicatethatmarketconditionsplayedaroleintheirdecision.[INSERTFIGURE2]
Whywould?rmsnotsimplywaitformorefavorablemarketconditions?Thereare
severalpossiblereasons.First,a?lingregistrationautomaticallyexpires270daysafterthelastamendmentoftheIPO?ling,whichlimitsthetimetocompletetheIPO?ling(Lerner(1994)).Additionally,waitingiscostly:aslongastheapplicationispending,?rmscannotissueprivateplacements,andareforbiddenfromdisclosingnewinformationtospeci?cinvestorsorbanks.Indeed,?rmsarerequiredtoupdatetheregistrationstatementperiodicallytore?ectthecurrenta?airsofthecompany.Theseconsiderationslead?rmstowithdrawpriortotheautomaticexpirationoftheIPO?ling.
13
This article is protected by copyright. All rights reserved.
The?rst-stageresults,presentedinTableII,demonstratethee?ectofNASDAQreturnsduringthebook-buildingphaseonIPOcompletion.Thedependentvariableisequaltooneifa?rmcompletestheIPO?ling,andzerootherwise.Allspeci?cationsinclude?lingyearandindustry?xede?ectsusingOLS.Incolumn(1),I?ndthatthecoe?cientontwo-monthNASDAQreturnsequals0.704andissigni?cantatthe1%level.AonestandarddeviationdeclineinNASDAQreturnstranslatesintoa8.72TcreaseinthelikelihoodofcompletingtheIPO.Moreover,theF-statisticequals47.79andexceedsthethresholdofF=10,whichsuggeststhattheinstrumentisstrongandunlikelytobebiasedtowardtheOLSestimates(Bound,Jaeger,andBaker(1995),StaigerandStock(1997)).[INSERTTABLEII]
Incolumn(2),Icontrolforthethree-monthNASDAQreturnspriortotheIPO?ling,
Accepted Articlethenumberofpre-?lingpatents,aVCbackingdummyvariable,andthelocationofthe?lerwithintheIPOwave.10Thecoe?cientremainshighlystatisticallysigni?cant,suggestingthattheinstrumentisalmostorthogonaltotheaddedcontrolvariables.Incolumns(3)and(4),Ilimitthesampletothepre-2000period.Theresultsremainsimilar.Incolumns(5)and(6),IcalculatetheNASDAQreturnsovertheentirebook-buildingperiod.11Thecoe?cientisstillsigni?cantatthe1%level,butthemagnitudeofthecoe?cientissomewhatlower.Incolumns(7)and(8),Iconstructadummyvariablethatequalsoneifthe?rmdoesnotexperienceaNASDAQdrop,wherea?rmisclassi?edashavingexperiencedaNASDAQdropifitstwo-monthNASDAQreturnfollowingtheIPO?lingisamongthelowest25%ofall?lerswithinthesameyear.Thedummyvariableincolumn(7)ishighlystatisticallysigni?cant,re?ectinga10.6%increaseinthelikelihoodofIPOcompletion.Column(8)addstheadditionalcontrolvariables.Theresultsagainremainunchanged.
Figure3illustratesthenonparametricrelationbetweenthetwo-monthNASDAQ?uctu-
ationsandthelikelihoodofcompletingtheIPO?ling.The?gureshowsthataslongastheNASDAQ?uctuationsarenegative,thereisapositiveandmonotonicassociationbetween
14
This article is protected by copyright. All rights reserved.
asmeasuredbynumberofpatents.Inthatcase,theadditionoflow-qualityinnovationprojectsmaygeneratetheresultsratherthanarepositioningofresearchtolower-impacttopics.TheanalysisinTableVIIIaddressesthisquestionbyexploringchangesinthescaleofinnovation.15
[INSERTTABLEVIII]
Theendogenousmodelincolumn(1)indicatesthatIPO?rmsproducesigni?cantly
Accepted ArticlemorepatentsperyearfollowingtheIPO?ling,witha37.75%increaserelativetothepre-IPOaverage.Column(2),however,indicatesthattheabovee?ectisinsigni?cantwhenthereduced-formspeci?cationisestimated.The2SLSestimateincolumn(3)showsthatthecoe?cientontheIPOvariableisinsigni?cantandthemagnitudedeclinesto28.17%.Infact,whenusingtheIVPoissonspeci?cationincolumn(4),thecoe?cientontheIPOvariableisclosetozeroandinsigni?cant.
A.3.
RobustnessChecksandInterpretation
InthissectionIsummarizeseveralsupplementalanalysesthattesttherobustnessand
interpretationoftheabove?ndings.IstartbyexploringwhetherthedeclineintheaverageinnovationqualityofIPO?rmscanbedrivenbyalowerpatentingthresholdaftertheIPO.Thismayleadtotheadditionoflow-qualitypatentsandhenceloweraveragepatentingquality.Todoso,Iexamine?rms’best(i.e.,most-cited)patent,whichisunlikelytobea?ectedbytheadditionoflow-qualitypatent?lings.I?ndthatthequalityofIPO?rms’bestpatentdeclinesaswell,withacomparablemagnitudeasthedeclineinaverageinnovationqualityreportedinTableVI.Thisevidence,whichisreportedintheInternetAppendix,suggeststhatgoingpublica?ectstheentirepatentdistributionratherthansimplydrivingaverageperformancedownbytheadditionoflow-qualityprojects.16
Next,cash-rich?rmsmaybeassociatedwithfewercitationsbecauseciting?rmsfacehigherlitigationrisk,whichwouldmechanicallygeneratetheresultsinthepaper.Totest
20
This article is protected by copyright. All rights reserved.
thisconcern,IfocusonpatentsapprovedbeforetheIPO?lingandexaminewhetherpatents’annualcitationratechangesafterthe?rmsgopublic(relativeto?rmsthatwithdrawthe?ling).InresultsreportedintheInternetAppendix,I?ndthatchangesinthecitationrateofexistinginventionscannotbeexplainedbythetransitiontopublicequitymarkets.IalsoexplorewhethertheresultsaredrivenbytheInternetbubbleyears.Asillustrated
Accepted ArticleinTableIV,theinstrumentstronglypredictsIPOcompletionevenwhenall?rmsthat?ledduringtheInternetbubbleandthereafterareexcluded.InrobustnesstestsIreestimatetheinnovationnoveltyregressionsafterexcludingall?rmsthat?letogopublicasof1999.Theresults,reportedintheInternetAppendix,remainsigni?cantandqualitativelyunchanged.Inthemainanalysis,Icollectinformationontheinnovationtrajectoryof?rmsinthe?ve
yearssubsequenttotheIPO?ling.Ininterpretingtheresults,itisnaturaltowonderhowtheendogenoustransitionof18%ofthewithdrawn?rmstopublicequitymarketsa?ectstheestimates.Toexaminethisquestion,Irepeattheinstrumentalvariablesanalysisusinganendogenousvariablethatequalsoneifa?rmgoespublicinthetwo(orthree)yearsaftertheIPO?ling,regardlessofwhetheritwithdrawsinthe?rstattempt.Thus,ifa?rmwithdrawsits?lingandreturnstotheIPOmarketinthe?rsttwo(three)yearsafterthe?ling,this?rmwouldbeconsideredpartofthetreatmentgroup(andnotthecontrolgroup).17As
reportedintheInternetAppendix,thesespeci?cationsgenerateestimatesthataresimilartothosereportedabove.
Finally,itisimportanttounderstandwhethertheestimatesaredrivenbychangesin
?rmsthatwithdrawtheirIPO?lingandremainprivateorby?rmsthatgopublic.Forexample,withdrawn?rmsmaychoosetoincreasetheirinnovationinordertosuccessfullygopublicinasecondattempt,ratherthanIPO?rmsexperienceadeclineininnovation.However,I?ndthatallIPO?lersexperienceadeclineinscaledinnovationmeasures,both?rmsthatexperienceaNASDAQdrop(andthusaremorelikelytoremainprivate)and?rmsthatdonotexperienceaNASDAQdrop.18However,thedeclineismoresubstantialamong?rmsthatendupgoingpublic.Similarly,changesintheacquisitionofexternalinnovation,
21
This article is protected by copyright. All rights reserved.
asdiscussedinSectionIII.C,aredrivenbythose?rmsthatgopublicratherthanthosethatremainprivate.19
Accepted ArticleB.InventorMobilityandProductivityChanges
AsubstantialportionofR&Dinvestmentisintheformofwagesforhighlyeducated
scientistsandengineers,whoencompassthe?rm’sknowledge.ItisthereforenaturaltoexplorewhethergoingpublicleadstoinventormobilityandproductivitychangesfollowingtheIPO.
B.1.InventorLevelData
Thepatentdatabaseprovidesaninterestingopportunitytotrackinventors’mobility
across?rms,aseachpatentapplicationincludesboththenameoftheinventoranditsassignee(mostoftentheinventor’semployer).Analysisofinventor-leveldata,however,ischallengingforseveralreasons.First,patentsareassociatedwithinventorsbasedontheirnameandgeographiclocation,butinventors’namesareunreliableas?rstnamescanbeabbreviatedanddi?erentinventorsmayhavesimilarorevenidenticalnames.Second,whileitispossibletoinferthataninventorchanged?rms(forexample,aninventorisassociatedwithapatentforcompanyAin1987andapatentforcompanyBin1989),theprecisedateoftherelocationisunavailable.Additionally,transitionsforwhichinventorsdonotproducepatentsinthenewlocationarenotobservable.Hence,thismethodidenti?esrelocationsofthemorecreativeinventorswhopatentfrequentlyandpresumablymatterthemost.Toovercomethehurdleofnamematching,IusetheHBSpatentingdatabase,whichin-
cludesuniqueinventoridenti?ers.Theuniqueidenti?ersarebasedonre?neddisambiguationalgorithmsthatseparatesimilarinventorsbasedonvariouscharacteristics(Lai,D’Amour,andFleming(2009)).Whenpatentapplicationsincludemultipleinventors,Iattributeapatentequallytoeachinventor.Overall,Iobtaininformationonapproximately36,000in-ventorsinmysample.Irestricttheanalysistoinventorsthatproduceatleastasinglepatent
22
This article is protected by copyright. All rights reserved.
bothbeforeandaftertheIPO?lingandexaminethepatentingbehaviorofinventorsinthethreeyearsbeforeand?veyearsaftertheIPO?ling.Iidentifythreeinventortypes:1.Stayer–AninventorwithatleastasinglepatentbeforeandaftertheIPO?lingatthesamesample?rm.
2.Leaver–Aninventorwithatleastasinglepatentatasample?rmbeforetheIPO?ling,andatleastasinglepatentinadi?erentcompanyaftertheIPO?ling.20
3.Newcomer–AninventorwithatleastasinglepatentaftertheIPO?lingatasample?rm,butnopatentsbefore,andatleastasinglepatentatadi?erent?rmbeforetheIPO?ling.
Ofthe36,000inventorsinmysample,Icanclassify16,108inventorsintotheabove
Accepted Articlecategories.21Theseinventorsaccountforapproximately65%ofthesamplepatents.
B.2.
InventorLevelAnalysis
Iexplorechangesininventor-levelactivityusingtheinstrumentalvariablesapproach
introducedinSectionII.A.Istartbyinvestigatingchangesintheinnovationqualityofstayers.Next,Iexamineinventormobilitybystudyinginventors’likelihoodofleaving,spinningo?acompany,orjoiningthe?rmfollowingtheIPO?ling.
TheresultsarereportedinTableIX,wheretheunitofobservationisatthelevelofthe
inventor.Incolumn(1),Iexplorechangesinstayers’productivity.Ifocusonthesetofinventorsthatremainatthe?rm,andthedependentvariableistheaveragescaledcitationsproducedbyinventorsinthe?veyearsaftertheIPO?ling.Icontrolfortheinventor’spre-IPO?lingcitationsperpatent,aswellas?lingyearandindustry?xede?ectsandtheotherstandardcontrols.Standarderrorsareclusteredatthe?rmlevel,toallowforcorrelationsbetweeninventorsinthesame?rm.Iestimatethe2SLSincolumn(1),and?ndthattheIPOcoe?cientequals-1.094,whichisstatisticallysigni?cantatthe1%level.Themagnitudeislarge,correspondingtoa48Tclineininventors’innovationnoveltyinIPO?rmsrelativeto
23
This article is protected by copyright. All rights reserved.
thepre-IPO?lingperiod.22These?ndingssuggestthatthedeclineinIPO?rms’innovationactivitycouldbeattributedatleastinparttoachangeinthequalityofinnovationproducedbyinventorswhoremainatthe?rm.[INSERTTABLEIX]
Toestimatewhethergoingpublicmaya?ectinventors’departure,Ifocusoninventors
Accepted Articlethatproducepatentsatthe?rmbeforetheIPO?ling,andexaminethelikelihoodthattheyleavethe?rm.Incolumn(2),Irunasimilarspeci?cationtothatreportedincolumn(1),butnowthedependentvariableequalsoneiftheinventorisclassi?edasaleaverandzeroifaninventorisastayer.The2SLSestimatesshowthatinventorsinIPO?rmsare18%morelikelytoleavethe?rmaftertheIPO,withthecoe?cientstatisticallysigni?cantatthe1%level.23ThisresultdemonstratesthatthedeclineinthequalityofinnovationofIPO?rmsispotentiallyalsodrivenbythedepartureofinventors.
Doestheincreasedinventordepartureratealsotranslateintoahigherrateofspin-o?s?
FollowingAgrawaletal.(2012),Iidentifyallpatentsproducedbyleaverspost-departureandthe?rmstowhichthesepatentsareassigned.Anassigned?rmisconsideredaspin-o?ifthenumberofappliedpatentsbeforetheleaver’spatentiszero.24Thisapproachprovidesanapproximationofwhetheraleaverstartedanewcompany.Whilenotperfect,inaccuraciesaresimilarlylikelytoa?ectleaversofIPOandwithdrawn?rms.
Irepeatthespeci?cationofcolumn(2),focusingoninventorswhoproducedpatentsina
sample?rmbeforetheIPO?ling,andexplorethelikelihoodthatcreateaspin-o?.The2SLSestimatesreportedincolumn(3)ofTableIXillustratethatIPO?rmsare9.5%morelikelytogeneratespin-o?scomparedtowithdrawn?rms,suggestingthatIPO?rms’leaversremainentrepreneurialfollowingtheirdeparture.Thisresultisalsoconsistentwiththe?ndingthattheleaversofIPO?rmsgeneratehigherqualitypre-IPOpatentsrelativetothestayers,incontrasttothecaseofwithdrawn?rms(SeetheInternetAppendix).
Finally,IexplorewhetherIPO?rmsaremorelikelytoattractnewinventors.Incolumn
24
This article is protected by copyright. All rights reserved.
(4)Irestricttheanalysistoinventorsthatgeneratepost-?lingpatentsinasample?rm,andasadependentvariableIuseanindicatorforwhetheraninventorisanewcomer.Usingthe2SLSspeci?cationI?ndthatIPO?rmsaresubstantiallymorelikelytohirenewinventors.Themagnitudeofthecoe?cientislarge,correspondingtoa38.8%increase.25
Theresultsrevealthatthetransitiontopublicequitymarketshasimportantimplications
Accepted Articleforthehumancapitalaccumulationprocess,asitshapes?rms’abilitytoretainandattractinventors.FollowingtheIPO,thereisanexodusofinventorsleavingthe?rm,andmorespin-o?saregeneratedfollowingtheirdeparture.Additionally,goingpublica?ectsthepro-ductivityoftheinventorswhoremainatthe?rm.TheaveragequalityofpatentsproducedbystayersdeclinessubstantiallyatIPO?rms.However,thise?ectismitigatedinpartbytheabilityofIPO?rmstoattractnewinventorswhoproducepatentsofhigherqualitythantheinventorswhoremainatthe?rm.
C.AcquisitionofExternalTechnologies
Inthissection,Iexplorehowthetransitiontopublicequitymarketsa?ects?rms’reliance
onexternaltechnologiespurchasedthroughmergersandacquisitions.26Icollectinformation
onallacquisitionsconductedbyIPOandwithdrawn?rmsusingtheSDCdatabase.27In
resultsreportedintheInternetAppendix,I?ndthatIPO?rmsexhibitasharpincreaseinM&Aactivityinthe?veyearsfollowingtheIPO,whilethereisnomeaningfule?ectforwithdrawn?rms.
Acquisitions,however,areusedforavarietyofreasons.Thequestionremainswhether
acquisitionsareusedtobuyexternaltechnologies.Icollectinformationonpatentsgeneratedbytarget?rmsintheyearspriortotheacquisitionbymatchingacquisitiontargetstotheNBERpatentsdatabase.28Approximately7,500patentswereacquiredthroughmergersandacquisitionsinthe?veyearsfollowingtheIPO?ling,relativetoapproximately30,000patentsproduced.IntheInternetAppendix,IshowthatbeforetheIPO?lingbothwithdrawnandIPO?rmsrarelyacquireexternalpatentsthroughM&A.FollowingtheIPO,however,the
25
This article is protected by copyright. All rights reserved.
fractionofexternalpatentsinIPO?rms’portfolioincreasesto31%whileitremainssmallforwithdrawn?rms(8%).
Similarpatternsarisewhenusingtheinstrumentalvariablesapproach.InTableX,the
Accepted Articledependentvariableisthenumberofexternalpatentsboughtthroughmergersandacquisi-tionsinthe?veyearsfollowingtheIPO?ling.Allspeci?cationsfollowthemodeldescribedinSectionII.A,controllingfor?lingyearandindustry?xede?ects.Ialsoaddalladditionalcontrolvariablespreviouslymentioned.Iestimatethe2SLSincolumn(3)and?ndthatIPO?rmsacquire2.6morepatentsperyearcomparedtowithdrawn?rms.[INSERTTABLEX]
Theidentifyingassumptionhereisthat,fortwo?rmsthatattempttogopublicinthe
sameyear,changesinshort-termNASDAQ?uctuationshaveasimilare?ectonthelikelihoodofacquiringexternalpatents.Tofurtheralleviateconcernsabouttheexclusionrestriction,incolumn(4)Ialsocontrolfortheindustryacquisitionintensityinthe?veyearsfollowingtheIPO?ling.29I?ndthattheresultscontinuetohold.IntheInternetAppendix,theseresultscanbealsoillustratedbycomparingsimpleaveragesbetween?rmsthatexperienceaNASDAQdropandother?lersinthesameyear,similartotheapproachtakeninTableV.Giventheincreasedrelianceonexternalpatents,itisinterestingtocomparetheexternal
andinternalpatentsofIPO?rms.IntheInternetAppendix,I?ndthatonaverageexternalpatentsexhibithigherqualitythanpatentsgeneratedinternally,asmeasuredbyaveragescaledcitations.30Overall,theresultssuggestthatgoingpublicleadstoenhancedreliance
onexternaltechnologies.
IV.PotentialChannels
Theempirical?ndingsthusfarillustratethatthetransitiontopublicequitymarkets
changes?rm’sinnovationstrategy.FollowingtheIPO,?rmsexperienceadeclineininno-vationquality,substantialinventorturnover,andanincreaseintheacquisitionofexternal
26
This article is protected by copyright. All rights reserved.
innovation.
Inthissection,Idiscussseveralpotentialexplanationsforthe?ndings.FollowingtheIPO,various?rmcharacteristicschange,andhenceanumberofpotentialstoriesmayarise.Ifocusonfoursuchexplanations.Thecorporate?nanceliteraturehaslongarguedthatpublicownershipentailsagencyproblemsbetweenmanagersandshareholdersduetotheseparationofownershipandcontrol(BerleandMeans(1932),JensenandMeckling(1976)).Therefore,I?rstfocusontwohypothesesbasedonagencyproblemsthatcanleadpubliclytraded?rmstoconducttoolittleinnovation.Speci?cally,motivatedbyAghion,VanReenen,andZingales(2013),Ifocusonthemanagerialcareerconcernsandthequietlifehypotheses.However,itmaybethecasethatagencyproblemsaremorepervasiveinprivate?rms,leadingtotoomuchinnovation.Thisalternativetheoryiscapturedbytheexcessiveinnovationhypothesis.Finally,Iconsiderthecaseinwhichtheresultsmaynotbedrivenbyagencyproblems.Inparticular,thisagency-freehypothesisismotivatedbytheassumptionthatcommercializationiscapital-intensiveandthuspossibleonlyfollowingtheIPO.
Idiscussthesehypothesesindetailbelow,andthenprovidesuggestiveempiricalevidence
Accepted Articleinanattempttodi?erentiatebetweenthesealternativestories.
A.Hypotheses
A.1.
CareerConcernsHypothesis
The?rsthypothesisisbasedonavariationofthecareerconcernstheory(Holmstrom
(1982)).Underthishypothesis,theprincipal-agentproblemoccursbetweenshareholdersandthemanager.Themanagergainsprivatebene?tsfromretainingherjob.Innovationmaycostthemanagerherjob,however,ifshareholdersattributeinnovationfailures,eventhoseduetopurelystochasticreasons,topoormanagerialskill.Asaresult,concernsabouttheimpactofinnovationoninvestors’perceptionofthemanager’sability,thatis,careerconcerns,leadtoanaversiontoinnovation.
Increasedmonitoringmayallowinvestorstodistinguishbetweenunluckynegativedraws
27
This article is protected by copyright. All rights reserved.
andmanagerialskill(Aghion,VanReenen,andZingales(2013)),whichwouldhelpinsulatethemanagerfromadversereputationalconsequencesofinnovation.Inprivate?rms,whereownershipisconcentrated,investorshavegreaterincentivetomonitorthemanager,whichshouldleadtomoreinnovation.Inpublicownership,incontrast,dispersedownershipleadstolowerincentivestomonitorwhichmaydissuadethemanagerfrominnovating.31
Anadditionalpredictionofthishypothesisisthatanentrenchedmanager,whosejobis
Accepted Articlemoresecure,maybewillingtoinnovaterelativelymoreaftertheIPO,asinnovationdoesnotexposethemanagertoasmuchriskoflosingherjob.
A.2.
QuietLifeHypothesis
Anotherhypothesisrelatedtotheagencyproblembetweenshareholdersandtheman-
agerisbasedontheideathatinnovationisadi?culttaskthatimposesaprivatecostonthemanager(forexample,itmayrequiredeviatingfromstandardroutines),deterringthemanagerfrominnovationactivity(basedonasimplevariationofHolmstromandTirole(1997)).Thishypothesis,whichissimilartothequietlifehypothesisofBertrandandMul-lainathan(2003),predictsthatinprivatelyownedcompanies,investormonitoringmayleadthemanagertoloseherjobifshedoesnotinnovate,whileunderpublicownership,weakerinvestorincentivetomonitormayallowthemanagertoinnovateless.ThishypothesisalsopredictsthatanentrenchedmanagerwillchoosetoinnovatelessfollowingtheIPO,asherjobismoresecure,incontrasttothecareerconcernshypothesis.
A.3.
ExcessiveInnovationHypothesis
Itmayalsobethecasethatprivate?rmsinnovatetoomuch.Iftheentrepreneurgains
privatebene?tsfrominnovation,asopposedtocommercialization,andsheisalsothelargestownerinaprivate?rmandthereforehascontrol,thentheentrepreneurmaychoosetofocustoomuchoninnovation.Here,theprincipal-agentproblemarisesbetweentheentrepreneur,whoisthelargestshareholder,andminorityshareholders.32Inpubliclytraded?rms,in
28
This article is protected by copyright. All rights reserved.
contrast,theentrepreneurisnotthelargestshareholderandhaslesscontrol,andthereforehaslessabilitytopursueexcessiveinnovation.
A.4.Agency-FreeHypothesis
Underthelasthypothesis,?rmschoosetogopublictocommercializeexistinginnovation.
Accepted ArticleCommercializationalonecannotexplaintheresults,asallsample?rmsareattemptingtogopublic.However,ifcommercializationiscapitalintensive(morethaninnovation),thenonlythose?rmsthatsuccessfullycompletetheIPOcanpursuecommercializationstrategy.Ifthefocusoncommercializationleads?rmstoinnovateless,thismayexplainthedeclineininnovationquality.Incontrast,?rmsthatremaineprivatedonothavetheresourcestocommercializeandthuscontinuetoinnovate.Importantly,forthishypothesistohold,itisnecessarytoassumethatsomelimitedresource,suchasmanagerialattention,prevents?rmsfrompursuingcommercializationandinnovationsimultaneously,despitetheimprovedaccesstocapitalfollowingtheIPO.
B.EmpiricalTests
Thissectionprovidessuggestiveempiricalevidenceinanattempttodistinguishbetween
thefourhypothesesabove.
B.1.
ExcessiveInnovationHypothesis
Theexcessiveinnovationhypothesispositsthatwhentheentrepreneurhascontrol,pri-
vate?rmsmayconducttoomuchinnovationthatmaynotnecessarilycontributeto?rmvalue.Toexplorethishypothesis,Icompare?rmsthatgopublicwithasetofprivate?rmsinwhichtheentrepreneurhasnocontrol.Speci?cally,Iconsiderprivate?rmsownedbyVC?rmsandmanagedbyaprofessionalmanager(thatis,anonfoundermanager).Theseprivate?rmsarelikelytosu?ertheleastfromagencyproblemsthatleadtoexcessiveinno-vation.IrepeatthemaininstrumentalvariablesanalysistoexaminetheIPOe?ectforsuch
29
This article is protected by copyright. All rights reserved.
private?rms(seetheInternetAppendix).I?ndthatevenVCownedprivatecompaniescon-ductsigni?cantlyhigherqualityinnovationintheyearsfollowingtheIPOrelativeto?rmsthatgopublic.Moreover,inventorsinsuchprivate?rmsaresigni?cantlylesslikelytoleave.Thisevidencesuggeststhatprivate?rmsdonotoverinvestininnovation,asconjecturedbytheexcessiveinnovationhypothesis,ascompaniesthatarelikelytosu?ertheleastfromagencyproblemsproducehigherqualityinnovation.
B.2.
Agency-FreeHypothesis
Accepted ArticleCantheagency-freehypothesisexplaintheresults?Ifimprovedaccesstocapitalallows
?rmstofocusoncommercialization,leadinginturntoadeclineininnovationquality,thensuchadeclineshouldbelessapparentin?rmsthatalreadyhavesigni?cantresourcesatthetimeoftheIPOorthatraiselittlecapitalthroughtheIPO.Such?rmsmaybethelargest?rmsthatgopublic,?rmswithhighcashrelativetoassetsatthetimeoftheIPO,and?rmsthatraisetheleastcapitalthroughprimaryshares.Suchadeclineshouldalsobelessapparentin?rmsthatfacelowercommercializationcosts,suchas?rmsinthesoftwareandservicesindustries.Toexaminethee?ectoftheIPOoneachofthesegroups,Irepeatthemaininstrumentalvariablesapproach,andreporttheresultsintheInternetAppendix.InallcasesIstill?ndasigni?cantdeclineininnovationquality.Whilethisevidenceisnotconclu-sive,itsuggeststhattheaccesstocapitalandpotentialabilitytopursuecommercializationafteranIPOdoesnotexplainthedeclineininnovationquality.
Inlightofevidenceintheliteraturethatinnovationiseconomicallyimportant(e.g.,Hall,
Ja?e,andTrajtenberg(2005),Koganetal.(2012)),itmaybesurprisingif?rmschoosenottopursueinnovationaftertheIPO.33Forexample,Koganetal.(2012)?ndthathigh-qualityinnovationpredicts?rmproductivityaswellascapitalandlabor?owsfromnon-innovativetoinnovative?rmswithinanindustry.Moreover,inthe“useofproceeds”sectionintheIPO?lingprospectus,I?ndthat75%of?rmsstatethattheyalsointendtouseproceedsfromtheIPOfortechnologicaldevelopmentandinnovation.34WhenIrepeatthemaininstrumental
30
This article is protected by copyright. All rights reserved.
variablesstrategyrestrictingthesampleto?rmsthatstateanintentiontoinnovate,asreportedintheInternetAppendix,I?ndasimilardeclineininnovationqualitysimilartothemain?ndings.35
B.3.
CareerConcernsandQuietLifeHypotheses
Accepted ArticleInlightoftheaboveevidence,Inextconsiderwhetherpubliclytraded?rmsunderinvest
ininnovationduetoagencyproblemsthatarisebetweenmanagementandshareholders.Consistentwiththemainresults,boththequietlifeandcareerconcernshypothesessuggestthatinnovationwilldeclinefollowingtheIPO.However,thesehypotheses,yielddi?erentpredictionswheninteractedwithmanagerialentrenchment.Managerialentrenchmentmayimproveinnovationunderthecareerconcernshypothesisbutdecreaseinnovationunderthequietlifehypothesis.Thesecontrastinge?ectsofmanagerialentrenchmentarediscussedbyFismanetal.(2013).
Iexploretheinteractionofgoingpublicwithmanagerialentrenchmentinane?ortto
distinguishbetweenthesetwohypotheses.Asaproxyformanagerialentrenchment,IuseadummyvariablethatcapturescasesinwhichtheCEOisalsothechairmanoftheboard(ShleiferandVishny(1989)).IhandcollectthisinformationfromIPOprospectuses.IntheInternetAppendix,Irepeatthemaininstrumentalvariablesanalysistoexaminethee?ectoftheIPOon?rminnovationseparatelyforentrenchedandnon-entrenchedCEOs.I?ndthat?rmswithnon-entrenchedmanagersexperienceasigni?cantdeclineininnovationqualityfollowingtheIPO,andinventorsofthese?rmsaremorelikelytoleave.Incontrast,suche?ectsdonotholdfor?rmswithentrenchedmanagement.Theseresultssupportthecareerconcernshypothesis.
C.Discussion
Overall,thissectiono?erssuggestiveevidencethatagencyproblemsbetweenmanage-
mentandshareholders,intheformofcareerconcerns,leadpubliclytraded?rmstopursue
31
This article is protected by copyright. All rights reserved.
lowerqualityinnovation.Theseresultsareconsistentwithrecentevidencethatexploresagencyproblemsinpublicequitymarketsinvarioussettings.36Forexample,Gao,Harford,andLi(2014)?ndthatpublic?rmsaremorelikelytoreplaceaCEO,relativetoprivate?rms,andthatsucheventsaremoresensitiveto?rmcontemporaneousperformance.Moreover,performancefollowingCEOdepartureismoremodestinpublic?rms.Related,Aghion,VanReenen,andZingales(2013)?ndthatinstitutionalinvestorsinpublic?rmsleadtomoreinnovation,andthelikelihoodofCEOturnoverfollowingarevenuedropislowerfor?rmswithgreaterinstitutionalownership.Thesepapersareconsistentwithcareerconcerns,whichmayleadmanagerstoselectmoreincrementalandlessriskyprojects.
Ifthepaper’smainresultsaredrivenbyagencyproblems,thenwhydo?rmsgopublic?
Accepted ArticleThisquestiongoesbacktoJensenandMeckling(1976).Therearemanycostsassociatedwiththedecisiontogopublic.Underwritingdirectexpenses,underpricing,increasedtrans-parency,andshort-termmarketpressuresarejustafewexamples.Thesecostsarebalancedbyvariousbene?tsfromgoingpublic,suchasimprovedaccesstocapital,increasedliquidity,greaterinvestordiversi?cation,andenhanced?rmreputation,amongothers(see,forexam-ple,Pagano,Panetta,andZingales(1998)andRitterandWelch(2002)).Anotherexampleofsuchbene?tsistheincreasedabilityof?rms,followingtheIPO,toacquireexternalinno-vationandattractnewinventors.Thesearetwoimportantmitigatingforcesthatalleviatethedeclineininternalinnovationandthedepartureofexistingemployees.
V.Conclusion
Inthispaper,IinvestigateanimportantyetunderstudiedaspectofIPOs,namely,theef-
fecton?rminnovation.The?ndingsinthispaperrevealacomplextrade-o?betweenpublicandprivateownership.Followingthetransitiontopublicequitymarkets,internalinnovationbecomeslessnovel,incomparisonwith?rmsthatwithdrawtheirIPO?lingandremainepri-vate.Inaddition,?rmsexperienceanexodusofskilledinventors.However,duetoincreased
32
This article is protected by copyright. All rights reserved.
accesstocapital,IPO?rmscanrelyonacquisitionoftechnologiesasanadditionalsourceofinnovationandcanattractnewhumancapital.Theseresultssuggestthatgoingpublicchangesthestrategiesthat?rmsemploywhenpursuinginnovation.Iproposefourpotentialexplanationsofthese?ndings,and?ndsuggestiveevidencethatsupportsmanagerialcareerconcerns.
Theseresultsrelatetoconcernsraisedbycorporatemanagers,bankers,andpolicymak-
Accepted ArticleersaboutwhethertherecentdeclineinIPOsmarksabreakdownintheengineofinnovationandgrowth(WeildandKim(2009)).ThepassageoftheJumpstartOurBusinessStar-tups(JOBS)Actaimstoeasetheabilityofyounger,fast-growingcompaniestoraisefundsthroughtheIPOmarket.Thispapershowsthat,beyondraisingcapital,goingpublica?ects?rms’internalprojectselection,humancapital,andoutsourcingstrategies,andthereforehasimportantimplicationswithrespecttotheoptimaltimingofgoingpublic.
33
This article is protected by copyright. All rights reserved.
REFERENCES
Aggarwal,Vikas,andDavidHsu,2013,Entrepreneurialexitsandinnovation,ManagementScience60,867-887.
Aghion,Philippe,andJeanTirole,1994,Themanagementofinnovation,QuarterlyJournalofEconomics109,1185-1209.
Aghion,Philippe,JohnVanReenen,andLuigiZingales,2013,Innovationandinstitutionalownership,Americaneconomicreview103,277-304.
Agrawal,AjayK.,IainM.Cockburn,AlbertoGalasso,andAlexanderOettl,2012,Whyaresomeregionsmoreinnovativethanothers?Theroleof?rmsizediversity,NBERWorkingpaper.
Akcigit,Ufuk,andWilliamR.Kerr,2013,Growththroughheterogeneousinnovations,NBERWorkingpaper.
Anton,JamesJ.,andDennisA.Yao,2004,Littlepatentsandbigsecrets:Managingintellectualproperty,RANDJournalofEconomics35,1-22.
Arrow,KennethJ.,1962,Economicwelfareandtheallocationofresourcesforinvention,inTheRateandDirectionofInventiveActivity(PrincetonUniversityPressandNBER).Asker,John,JoanFarre-Mensa,andAlexanderLjungqvist,2014,Corporateinvestmentandstockmarketlisting:Apuzzle?,Workingpaper,NewYorkUniversity.
Bennedsen,Morten,FranciscoP′erez-Gonz′alez,andDanielWolfenzon,2010,Thegover-nanceoffamily?rms,inRonaldAndersonandKurtBaker,Eds:CorporateGovernance:ASynthesisofTheory,Research,andPractice(Wiley&Sons).
Benveniste,LawrenceM.,AlexanderLjungqvist,WilliamJ.WilhelmJr,andXiaoyunYu,2003,Evidenceofinformationspilloversintheproductionofinvestmentbankingservices,JournalofFinance58,577–608.
Accepted ArticleBerle,AdolfA.,andGardinerC.Means,1932,TheModernCorporationandPrivateProp-erty(Macmillan,NewYork).
Bertrand,Marianne,andSendhilMullainathan,2003,Enjoyingthequietlife?Corporategovernanceandmanagerialpreferences,JournalofPoliticalEconomy111,1043-1075.
Beshears,John,2013,Theperformanceofcorporatealliances:EvidencefromoilandgasdrillingintheGulfofMexico,JournalofFinancialEconomics110,324-346.
Blundell,RichardW.,andJamesL.Powell,2004,Endogeneityinsemiparametricbinaryresponsemodels,ReviewofEconomicStudies71,655-679.
Bound,John,DavidA.Jaeger,andReginaM.Baker,1995,Problemswithinstrumentalvariablesestimationwhenthecorrelationbetweentheinstrumentsandtheendogeneousexplanatoryvariableisweak,JournaloftheAmericanStatisticalAssociation90,443-450.
34
This article is protected by copyright. All rights reserved.
Brau,JamesC.,andStanleyE.Fawcett,2006,Initialpublico?erings:Ananalysisoftheoryandpractice,JournalofFinance61,399-436.
Brav,Alon,andPaulA.Gompers,1997,Mythorreality?Thelong-rununderperformanceofinitialpublico?erings:Evidencefromventureandnonventurecapital-backedcompanies,JournalofFinance52,1791-1821.
Brav,Omer,2009,Accesstocapital,capitalstructure,andthefundingofthe?rm,JournalofFinance64,263-308.
Busaba,WalidY.,LawrenceM.Benveniste,andRe-JinGuo,2001,TheoptiontowithdrawIPOsduringthepremarket:Empiricalanalysis,JournalofFinancialEconomics60,73–102.
Carter,RichardB.,FrederickH.Dark,andAjaiK.Singh,1998,Underwriterreputation,initialreturns,andthelong-runperformanceofIPOstocks,JournalofFinance53,285-311.Carter,RichardB.,andStevenManaster,1990,Initialpublico?eringsandunderwriterreputation,JournalofFinance4,1045-1067.
Accepted ArticleChemmanur,ThomasJ.,ShanHe,andDebarshiK.Nandy,2010,Thegoing-publicdecisionandtheproductmarket,ReviewofFinancialStudies23,1855-1908.
Degeorge,Francois,andRichardZeckhauser,1993,ThereverseLBOdecisionand?rmperformance:Theoryandevidence,JournalofFinance4,1323-1348.
Dunbar,CraigG,1998,Thechoicebetween?rm-commitmentandbest-e?ortso?eringmethodsinIPOs:Thee?ectofunsuccessfulo?ers,JournalofFinancialIntermediation7,60-90.
Dunbar,CraigG.,andStephenR.Foerster,2008,Secondtimelucky?WithdrawnIPOsthatreturntothemarket,JournalofFinancialEconomics87,610–635.
Edelen,RogerM.,andGregoryB.Kadlec,2005,IssuersurplusandthepartialadjustmentofIPOpricestopublicinformation,JournalofFinancialEconomics77,347–373.Fisman,RaymondJ.,RakeshKhurana,MatthewRhodes-Kropf,andSoojinYim,2013,GovernanceandCEOturnover:Dosomethingordotherightthing?ManagementScience60,319-337.
Gao,Huasheng,Po-HsuanHsu,andKaiLi,2014,Publicequitymarketsandcorporateinnovationstrategies:evidencefromprivate?rms,Workingpaper,UniversityofBritishColumbia.
Gao,Huasheng,JarradHarford,andKaiLi,2014,InvestorhorizonandCEOturnover-performancesensitivity,Workingpaper,UniversityofBritishColumbia.
Griliches,Zvi,1990,Patentstatisticsaseconomicindicators:Asurvey,JournalofEconomicLiterature28,1661-1707.
35
This article is protected by copyright. All rights reserved.
Hall,BronwynH.,ZviGriliches,andJerryA.Hausman,1986,PatentsandR&D:Istherealag?InternationalEconomicReview27,265-283.
Hall,BronwynH.,AdamJa?e,andManuelTrajtenberg,2001,TheNBERpatentcitationdata?le:Lessons,insightsandmethodologicaltools,NBERWorkingpaper8498.Hall,BronwynH.,AdamJa?e,andManuelTrajtenberg,2005,Marketvalueandpatentcitations,RANDJournalofEconomics36,16–38.
Hall,BronwynH.,andJoshLerner,2010,The?nancingofR&Dandinnovation,inBronwynH.HallandNathanRosenberg,eds.:HandbookoftheEconomicsofInnovation,(Elsevier-North,Holland).
Holmstrom,Bengt,1982,Managerialincentiveproblems-Adynamicperspective,inEssaysinEconomicsandManagementinHonorofLarsWahlbeck,(SwedishSchoolofEconomics,Helsinki).
Holmstrom,Bengt,andJeanTirole,1997,Financialintermediation,loanablefunds,andtherealsector,QuarterlyJournalofEconomics112,663-691.
Ibbotson,Roger,andJayR.Ritter,1995,Initialpublico?erings,inRobertA.Jar-row,VojislavMaksimovic,andWilliamT.Ziemba,eds.:HandbooksofOperationsResearchandManagementScience(North-Holland,Amsterdam)
Imbens,GuidoW.,andJoshuaD.Angrist,1994,Identi?cationandestimationoflocalaveragetreatmente?ects,Econometrica62,467-475.
Accepted ArticleJa?e,AdamB.,andManuelTrajtenberg,2002,Patents,Citations,andInnovations:AWindowontheKnowledgeEconomy(MITPressBooks).
Jain,BharatA.,andOmeshKini,1994,Thepost-issueoperatingperformanceofIPO?rms,JournalofFinance49,1699-1726.
Jensen,Michael,andWilliamH.Meckling,1976,Theoryofthe?rm:Managerialbehavior,agencycostsandownershipstructure,JournalofFinancialEconomics3,305-360.Kogan,Leonid,DimitrisPapanikolaou,AmitSeru,andNoahSto?man,2012,Technologicalinnovation,resourceallocation,andgrowth,NBERWorkingpaper.
Lach,Saul,andMarkSchankerman,1989,DynamicsofR&Dandinvestmentinthescien-ti?csector,JournalofPoliticalEconomy97,880-904.
Lai,Ronald,AlexanderD’Amour,andLeeFleming,2009,Thecareersandco-authorshipnetworksofUSpatent-holderssince1975,WorkingPaper,HarvardUniversity.
Lanjouw,JeanO.,ArielPakes,andJonathanPutnam,1998,Howtocountpatentsandvalueintellectualproperty:Theusesofpatentrenewalandapplicationdata,JournalofIndustrialEconomics46,405–432.
36
This article is protected by copyright. All rights reserved.
Lerner,Josh,1994,Venturecapitalistsandthedecisiontogopublic,JournalofFinancialEconomics35,293–316.
Lerner,Josh,MortenSorensen,andPerStr¨omberg,2011,Privateequityandlong-runinvestment:Thecaseofinnovation,JournalofFinance66,445-477.
Accepted ArticleLoughran,Tim,andJayR.Ritter,2004,WhyhasIPOunderpricingincreasedovertime?,FinancialManagement33,5-37.
Michaely,Roni,andMichaelR.Roberts,2012,Corporatedividendpolicies:Lessonsfromprivate?rms,ReviewofFinancialStudies25,711-746.
Mikkelson,WayneH.,MeganM.Partch,andKshitijShaw,1997,Ownershipandoperatingdecisionsofcompaniesthatgopublic,JournalofFinancialEconomics44,281-307.Moser,Petra,2007,Whydon’tinventorspatent?NBERWorkingpaper.
Netter,Je?ry,MikeStegemoller,andM.BabajideWintoki,2011,Implicationsofdatascreensonmergerandacquisitionanalysis:Alargesamplestudyofmergersandacquisitionsfrom1992to2009,ReviewofFinancialStudies24,2316-2357.
Pagano,Marco,FabioPanetta,andLuigiZingales,1996,Thestockmarketasasourceofcapital:Somelessonsfrominitialpublico?eringsinItaly,EuropeanEconomicReview40,1057-1069.
Pagano,Marc,FabioPanetta,andLuigiZingales,1998,Whydo?rmsgopublic?Anempiricalanalysis,JournalofFinance53,27-64.
P′astor,Lubos,LucianTaylor,andPietroVeronesi,2009,Entrepreneuriallearning,theIPOdecision,andthepost-IPOdropin?rmpro?tability,ReviewofFinancialStudies22,3005.Ritter,JayR.,andIvoWelch,2002,AreviewofIPOactivity,pricing,andallocations,JournalofFinance57,1795-1828.
Robinson,David,2008,Strategicalliancesandtheboundariesofthe?rm,ReviewofFi-nancialStudies21,649-681.
Saunders,Anthony,andSaschaSte?en,2011,Thecostsofbeingprivate:Evidencefromtheloanmarket,ReviewofFinancialStudies24,4091-4122.
Seru,Amit,2014,Firmboundariesmatter:EvidencefromconglomeratesandR&Dactivity,JournalofFinancialEconomics111,381-405.
Sheen,Albert,2009,Dopublicandprivate?rmsbehavedi?erently?Anexaminationofinvestmentinthechemicalindustry,Workingpaper,UCLA.
Shleifer,Andrei,andRobertW.Vishny,1989,Managemententrenchment::Thecaseofmanager-speci?cinvestments,JournalofFinancialEconomics25,123–139.
37
This article is protected by copyright. All rights reserved.
Solow,RobertM.,1957,Technicalchangeandtheaggregateproductionfunction,ReviewofEconomicsandStatistics39,312–320.
Staiger,Douglas,andJamesH.Stock,1997,Instrumentalvariablesregressionwithweakinstruments,Econometrica65,557-586.
Stein,JeremyC.,1989,E?cientcapitalmarkets,ine?cient?rms:Amodelofmyopiccorporatebehavior,QuarterlyJournalofEconomics104,655–669.
Accepted ArticleTrajtenberg,Manuel,RebeccaHenderson,andAdamJa?e,1997,Universityversuscorpo-ratepatents:Awindowonthebasicnessofinvention,EconomicsofInnovationandNewTechnology5,19–50.
Weild,David,andEdwardKim,2009,Awake-upcallforAmerica.GrantThornton(CapitalMarketsSeries).
38
This article is protected by copyright. All rights reserved.
TableI
SummaryStatistics
Thistableprovideskeysummarystatistics,comparing?rmsthatgopublicwith?rmsthatwithdrawIPO?lingandremainprivate.Allvariablesarede?nedintheAppendix.Averageinnovationmeasuresarecalculatedoverthethreeyearsupto(andthrough)theIPO?lingyear.FinancialinformationandIPOcharacteristicsareatthetimeoftheIPO?ling.Firmexitssuchasacquisition,bankruptcy,andsecondIPOarecalculatedoverthe?veyearsaftertheIPO?ling.*,**,and***indicatethatdi?erencesinmeansarestatisticallysigni?cantatthe10%,5%,and1%level,respectively.
Accepted ArticleCompletedWithdrawnMeanMedianS.D.MeanMedianS.D.Di?erence
InnovationMeasuresintheThreeYearsBeforeIPOFilingCitations12.697.2521.6010.916.0016.831.78ScaledCitations1.891.411.731.801.311.940.09NumberofPatents8.202.0050.067.002.0015.001.21ScaledNumberofPatents2.960.8511.162.720.935.070.24Generality0.450.470.210.460.500.22?0.01Originality0.470.500.210.480.490.23?0.01ScaledBestPatent4.302.895.714.002.494.920.31FinancialInformationatIPOFiling(from1996)LogTotalAssets3.072.910.052.972.93R&D/Assets0.290.210.310.290.19NetIncome/Assets?0.31?0.110.48?0.44?0.21Cash/Assets0.280.200.260.360.32IPOCharacteristics
LeadUnderwriterRankingFirmAgeVCBacked
Post-FilingNASDAQReturnsPre-FilingNASDAQReturnsPioneer
EarlyFollower
0.110.310.470.29?0.090.010.13***?0.08***
8.1611.940.460.030.070.020.059.001.278.179.008.0010.9811.147.000.000.500.511.000.030.11?0.06?0.050.060.120.050.050.000.140.030.000.000.220.070.00IPOFiling0.000.170.000.42--
1.3310.380.500.140.160.170.26?0.010.80?0.05*0.09***0.02***?0.01?0.02
FirmExitsintheFiveYearsAftertheBankruptcy0.02Acquisition0.24SecondIPO-
0.02
0.290.180.000.000.000.150.460.360.00?0.05-
39
This article is protected by copyright. All rights reserved.
TableIIFirstStage
Thistablereportsthe?rst-stageestimationoftheinstrumentalvariablesanalysis.Thedependentvariableisadummyvariablethatequalsoneifa?rmcompletestheIPO?ling,andzerootherwise.NASDAQReturnsisconstructeddi?erentlyacrossspeci?cations.Incolumns(1)to(4),NASDAQreturnsarethetwo-monthreturnsaftertheIPO?lingdate.Incolumns(5)and(6),NASDAQreturnsarecalculatedovertheentirebook-buildingperiod,thatis,fromthedateoftheinitialregistrationstatementtothecompletionorwithdrawaldate.Finally,columns(7)and(8)useadummyvariablethatisequaltooneifa?rmdoesnotexperienceaNASDAQdrop,wherea?rmissaidtohaveexperiencedaNASDAQdropifthetwo-monthNASDAQreturnsfromthedateoftheIPO?lingarewithinthebottom25%ofall?lersinthesameyear.Incolumns(3)and(4)thesampleisrestrictedtoIPO?lingsbefore2000.Whencontrolvariablesareincluded,thefollowingvariablesareaddedtothespeci?cation:three-monthNASDAQreturnspriortotheIPO?ling,numberofpatentsinthethreeyearsbeforetheIPO?ling,VCBacked,Pioneer,andEarlyFollower.Allvariablesarede?nedintheAppendix.ThemodelisestimatedusingOLS,androbuststandarderrorsarepresentedinparentheses.*,**,and***indicatethatthecoe?cientisstatisticallysigni?cantatthe10%,5%,and1%level,respectively.
(1)FullTwoMonths
(2)FullTwoMonths
(3)Pre-2000TwoMonths
(4)Pre-2000TwoMonths
(5)FullAll
(6)FullAll
(7)FullBinary
(8)FullBinary
Accepted ArticleSample
InstrumentNADSAQreturnsObservationsR2
FilingyearFEIndustryFE
ControlvariablesF-statistic
0.704***0.763***0.690***0.723***0.381***0.400***0.106***0.111***(0.102)(0.106)(0.128)(0.132)(0.080)(0.081)(0.022)(0.022)1,8010.138yesyesno47.79
1,8010.149yesyesyes52.03
1,4580.082yesyesno28.9
1,4580.089yesyesyes29.9
1,8010.127yesyesno22.63
1,8010.136yesyesyes24.13
1,8010.124yesyesno24.16
1,8010.134yesyesyes25.99
40
This article is protected by copyright. All rights reserved.
TableIII
NASDAQDropsandFirmCharacteristics
Tablepresentsdi?erencesin?rmcharacteristicsandinnovationperformancebetweenIPO?lersthatexperienceaNASDAQdropandother?lersinthesameyear.A?rmissaidtohaveexperiencedaNASDAQdropifitstwomonthNASDAQreturnsfollowingtheIPO?lingisatthebottomofthedistributionofallIPO?lersinthesameyear.Incolumn(1)Bottom10%referstoall?rmsthatexperiencethelowest10%NASDAQreturnsofallIPO?lerswithinayear,andincolumn(2)Top90%referstotheremaining?rms.Incolumn(4)Bottom25%referstoall?rmsthatexperiencethelowest25%NASDAQreturnswithinayear,andincolumn(5)Top75%referstoallremaining?rms.Allvariablesarede?nedintheAppendix.*,**,and***indicatethatdi?erencesinmeansarestatisticallysigni?cantatthe10%,5%,and1%level,respectively.
Accepted Article(1)(2)(3)(4)(5)(6)
NASDAQReturnsThreshold:BottomTopDi?erenceBottomTopDi?erence
10?%u%
Pre-FilingFinancialInformationTotalAssets3.163.060.1043.133.050.077R&D/Assets0.260.260.0070.260.26?0.002NetIncome/Assets?0.32?0.330.008?0.34?0.33?0.014Cash/Assets0.320.280.0360.300.290.013Sales/Assets0.860.89?0.0240.850.90?0.051IPOCharacterisitics
LeadUnderwriterRankingFirmAgeatFilingVCBacked
8.2211.870.468.0911.810.490.1240.068?0.0298.1911.100.498.0812.050.500.110?0.946?0.011
Pre-FilingPatentCharacteristicsCitations13.38ScaledCitations1.81NumberofPatents8.53ScaledNumberofPatents3.21ScaledGenerality1.11ScaledOriginality1.03ScaledBestPatent4.06
12.48
1.877.922.881.121.074.260.905?0.0700.6030.330?0.020?0.039?0.19712.631.926.972.671.141.064.4512.571.858.322.991.121.074.170.0640.072?1.354?0.3260.023?0.0170.277
41
This article is protected by copyright. All rights reserved.
TableIVPlaceboTest
Thistablereportsaplacebotesttoassessthevalidityoftheinstrumentalvariableexclusionre-striction.Thedependentvariableistheaveragescaledcitationsinthe?veyearsaftertheIPO?ling.ReturnsfollowingIPO?lingarethetwo-monthNASDAQreturnscalculatedfromtheIPO?lingdate.ReturnsfollowingIPOoutcomearethetwo-monthNASDAQreturnscalculatedfromeitherthedateoftheequityissuanceorthedateoftheIPO?lingwithdrawal.WhenthedateofIPO?lingwithdrawalisnotavailable,270dayssubsequenttothelastamendmentoftheIPO?lingisassumed(Lerner(1994)).ReturnsinyearbeforeIPO?lingarethetwo-monthNASDAQreturnscalculatedfromayearbeforetheIPO?ling.ReturnsinyearafterIPO?lingarethetwo-monthNASDAQreturnscalculatedfromayearaftertheIPO?ling.Thevariablesincludedintheregressionsarepre-?lingaveragescaledcitations,pre-?lingnumberofpatents,VCBacked,Pioneer,EarlyFollower,andthethree-monthNASDAQreturnsbeforetheIPO?ling.Allvariablesarede?nedintheAppendix.ThemodelisestimatedusingOLS,androbuststandarderrorsarereportedinparentheses.*,**,and***indicatethatthecoe?cientisstatisticallysigni?cantatthe10%,5%,and1%level,respectively.
(1)
(2)
(3)
(4)
(5)
(6)
(7)
Accepted ArticleDependentVariableReturnsfollowingIPO?lingReturnsfollowingIPOoutcomeReturnsinyearbeforeIPO?ling
ScaledScaledScaledScaledScaledScaledScaledCitationsCitationsCitationsCitationsCitationsCitationsCitations?0.498**(0.239)
0.207(0.251)
0.201(0.254)
?0.482**?0.495**?0.509**(0.237)(0.237)(0.241)0.162(0.248)
0.193(0.252)
0.0060.037(0.096)(0.094)10790.239yesyesyes
10790.242yesyesyes
10790.242yesyesyes
10790.242yesyesyes
ReturnsinyearafterIPO?lingObservationsR2
FilingyearFEIndustryFE
Controlvariables
10790.242yesyesyes
10790.240yesyesyes
10790.239yesyesyes
42
This article is protected by copyright. All rights reserved.
TableVReducedForm
Thistablereportsdi?erencesinthe?ve-yearinnovationperformancefollowingtheIPO?lingbe-tween?lersthatexperienceaNASDAQdropandother?lersinthesameyear.A?rmissaidtohaveexperiencedaNASDAQdropifthetwo-monthNASDAQreturnsaftertheIPO?lingarewithinthebottom25%ofall?lersinthesameyear.IPOisadummyvariableequaltooneifa?rmcompleteitsIPO?ling,andzerootherwise.Allvariablesarede?nedintheAppendix.*,**,and***indicatethatthedi?erenceinmeansisstatisticallysignicantatthe10%,5%,and1%level,respectively.
Accepted ArticleNASDAQDropMeanMedianS.D.IPO0.741.000.44ScaledCitations1.120.881.21ScaledNumberofPatents5.561.9112.42ScaledGenerality1.101.100.67ScaledOriginality1.091.090.39ScaledBestPatent3.612.104.66NoNASDAQDrop
MeanMedianS.D.Di?erence0.851.000.36?0.111***0.990.810.860.134**5.911.4916.64?0.3511.101.090.67?0.0051.041.060.430.047*2.891.943.130.721***
43
This article is protected by copyright. All rights reserved.
TableVI
InnovationNovelty
Thistablereportsthee?ectofanIPOoninnovationnovelty.Thedependentvariableistheaveragescaledcitationsinthe?veyearsaftertheIPO?ling.IPOisadummyvariableequaltooneifa?rmcompletetheIPO?ling,andzerootherwise.NASDAQReturnsisthetwo-monthNASDAQreturnscalculatedfromtheIPO?lingdate.Controlvariablesincludedintheregressionsare:pre-?lingaveragescaledcitations,pre-?lingaveragescalednumberofpatentsperyear,VCBacked,Pioneer,EarlyFollower,andthethree-monthNASDAQreturnsbeforetheIPO?ling.Allvariablesarede?nedintheAppendix.Incolumns(1)and(2)themodelisestimatedusingOLS,andincolumn(3)itisestimatedusing2SLS.Incolumn(4)theinstrumentalvariablesapproachisestimatedusingaquasi-maximumlikelihoodPoissonmodel.Inallspeci?cations,marginale?ectsarereported.MagnitudeistheratioofIPOcoe?cienttothepre-?lingaverageaverageofscaledcitations.Robuststandarderrorsarereportedinparentheses.Thestandarderrorsincolumn(4)arecorrectedusingthedeltamethod.*,**,and***indicatethatthecoe?cientisstatisticallysigni?cantatthe10%,5%,and1%level,respectively.
(1)ScaledCitationsOLS?0.019(0.069)
?0.498**(0.239)
-1.02%1,0790.239yesyesyes
-1,0790.242yesyesyes
-43.51%1,0790.128yesyesyes
-52.41%1,0790.148yesyesyes
(2)ScaledCitationsOLS
(3)ScaledCitations2SLS?0.831**(0.409)
(4)ScaledCitationsPoisson?0.980**(0.427)
Accepted ArticleDependentVariableModelIPO
NASDAQReturnsMagnitudeObservationsR2
FilingyearFEIndustryFE
Controlvariables
44
This article is protected by copyright. All rights reserved.
TableVII
FundamentalNatureofResearch
Thistablereportsthee?ectofanIPOonthefundamentalnatureofresearch.Incolumns(1)to(3)thedependentvariableistheaveragescaledoriginalityinthe?veyearsaftertheIPO?ling,andincolumns(4)to(6)itisaveragescaledgenerality.IPOisadummyvariableequalstooneifa?rmcompletestheIPO?ling,andzerootherwise.NASDAQReturnsisthetwo-monthNASDAQreturnscalculatedfromtheIPO?lingdate.Incolumns(1)to(3)Icontrolforthepre-?lingaveragescaledoriginality,andincolumns(4)to(6)Icontrolforthecorrespondinggeneralitymeasure.Additionalcontrolvariablesare:pre-?lingaveragescaledcitations,pre-?lingaveragescaledpatentsperyear,VCBacked,Pioneer,EarlyFollower,andthethree-monthNASDAQreturnsbeforetheIPO?ling.Allvariablesarede?nedintheAppendix.ThemodelisestimatedusingOLSincolumns(1),(2),(4),and(5)andusing2SLSincolumns(3)and(6).MagnitudeistheratioofIPOcoe?cienttothepre-?lingaverageofscaledoriginalityorscaledgenerality.Robuststandarderrorsarereportedinparentheses.*,**,and***indicatethatthecoe?cientisstatisticallysigni?cantatthe10%,5%,and1%level,respectively.
(1)(2)(3)(4)(5)(6)
DependentVariableScaledScaledScaledScaledScaledScaled
OriginalityOriginalityOriginalityGeneralityGeneralityGenerality
ModelOLSOLS2SLSOLSOLS2SLSIPO
NASDAQReturnsMagnitudeObservationsR2
FilingyearFEIndustryFE
Controlvariables
-0.10%1,0790.231yesyesyes?0.006(0.010)
?0.081**(0.036)
-1,0790.234yesyesyes
-13%1,0790.102yesyesyes
0%1,0790.226yesyesyes
?0.137**?0.001(0.068)(0.016)
?0.050
(0.051)
-1,0790.226yesyesyes
-8%1,0790.206yesyesyes?0.087(0.092)
Accepted Article45
This article is protected by copyright. All rights reserved.
TableVIIIInnovationScale
Thistablereportsthee?ectofanIPOoninnovationscale.Thedependentvariableistheaveragescalednumberofpatentsperyearinthe?veyearsaftertheIPO?ling.IPOisadummyvariableequalstooneifa?rmcompletestheIPO?ling,andzerootherwise.NASDAQReturnsisthetwo-monthNASDAQreturnscalculatedfromtheIPO?lingdate.Controlvariablesincludedinregressionsare:pre-?lingaveragescaledcitations,pre-?lingaveragescalednumberofpatentsperyear,VCBacked,Pioneer,EarlyFollower,andthethree-monthNASDAQreturnsbeforetheIPO?ling.Allvariablesarede?nedintheAppendix.ThemodelisestimatedusingOLSincolumns(1)and(2),and2SLSincolumn(3).Columns(4)estimatesthespeci?cationusingaquasimaximumlikelihoodPoissonmodel.Inallspeci?cations,marginale?ectsarereported.MagnitudeistheratiooftheIPOcoe?cienttothepre-?lingscalednumberofpatentsperyear.Robuststandarderrorsarereportedinparentheses.*,**,and***indicatethatthecoe?cientisstatisticallysigni?cantatthe10%,5%,and1%level,respectively.
(1)ScaledPatentsOLS0.268***(0.066)
(2)ScaledPatentsOLS
(3)ScaledPatents2SLS0.200(0.474)
(4)ScaledPatentsPoisson0.002(0.662)
Accepted ArticleDependentVariableModelIPONASDAQReturnsMagnitudeObservationsR2
FilingyearFEIndustryFE
ControlVariables
0.127(0.305)
37.75%1,8010.184yesyesyes
1,8010.178yesyesyes
28.17%1,8010.184yesyesyes
0.28%1,8010.168yesyesyes
46
This article is protected by copyright. All rights reserved.
TableIX
InventorMobilityandInnovativeProductivity
Thistablereportsthee?ectsofanIPOoninventors’mobilityandinnovativeactivity.Inventorsareclassi?edintothreecategories:stayers,leavers,andnewcomers,asde?nedinthetext.Incolumn(1)thesampleisrestrictedtostayersandthedependentvariableistheaveragescaledcitationsaftertheIPO?ling.Incolumns(2)and(3),thesampleincludesstayersandleavers,andthedependentvariableequalsoneiftheinventorleavesthe?rmorgeneratesaspin-o?,respectively.Anassigneeisconsideredaspin-o?ifthenumberofappliedpatentsbeforetheleaver’spatentiszero.Incolumn(4)thesampleincludesstayersandnewcomers,andthedependentvariableequalsoneiftheinventorjoinsthe?rm.IPOisadummyvariableequaltooneifa?rmcompletestheIPO?ling,andzerootherwise.Theinstrumentisthetwo-monthNASDAQreturnscalculatedfromtheIPO?lingdate.Inallspeci?cationsIcontrolfortheinventor’spre-IPO?lingaveragescaledcitationsandscalednumberofpatents.Additionalcontrolvariablesare:VCBacked,Pioneer,EarlyFollower,andthethree-monthNASDAQreturnsbeforetheIPO?ling.Allvariablesarede?nedintheAppendix.Allmodelsareestimatedusing2SLS.MagnitudeistheratiooftheIPOcoe?cienttothepre-?lingaverageofscaledcitations.Robuststandarderrorsarereportedinparentheses.*,**,and***indicatethatthecoe?cientisstatisticallysigni?cantatthe10%,5%,and1%level,respectively.
Accepted Article(1)(2)(3)DependentVariableCitationsofLikelihoodLikelihood
StayersofLeavingofaSpin-o?
Model2SLS2SLS2SLSIPO-1.094**0.183***0.095**(0.457)(0.062)(0.048)
Magnitude-47.94%-Observations665787738773R20.2030.0170.03FilingyearFEyesyesyesIndustryFEyesyesyesControlVariablesyesyesyes(4)LikelihoodofHiring2SLS0.388***(0.078)-116780.058yesyesyes
47
This article is protected by copyright. All rights reserved.
TableX
AcquisitionofExternalTechnologies
Thistablereportsthee?ectsofanIPOonthenumberofexternalpatentsacquiredthroughmergersandacquisitions.Thedependentvariableistheaveragenumberofexternalpatentsacquiredperyearinthe?veyearsaftertheIPO?ling.IPOisadummyvariableequaltooneifa?rmcompletestheIPO?ling,andzerootherwise.NASDAQReturnsisthetwo-monthNASDAQreturnscalculatedfromtheIPO?lingdate.Controlvariablesincludedinregressionsare:pre-?lingaveragescaledcitations,pre-?lingaveragescalednumberofpatentsperyear,VCBacked,Pioneer,EarlyFollower,andthethree-monthNASDAQreturnsbeforetheIPO?ling.Allvariablesarede?nedintheAppendix.ThemodelisestimatedusingOLSincolumns(1)and(2),andusing2SLSincolumn(3)and(4).Column(4)alsocontrolsforindustryacquisitionintensity,de?nedasthetotalvolumeofacquisitionswithinanindustrynormalizedbythetotalmarketvalueofall?rmsinthatindustry.Robuststandarderrorsarereportedinparentheses.*,**,and***indicatethatthecoe?cientisstatisticallysigni?cantatthe10%,5%,and1%level,respectively.
Accepted ArticleDependentVariableModelIPONASDAQReturnsObservationsR2
FilingyearFEIndustryFE
Controlvariables
AcquisitionPropensity
(1)ExternalPatentsOLS0.630***(0.154)
(2)ExternalPatentsOLS
(3)(4)ExternalExternalPatentsPatents2SLS2SLS2.603**2.489*(1.277)(1.288)
1,8010.366yesyesyesno
1.636**(0.785)1,8010.365yesyesyesno
1,8010.347yesyesyesno1,8010.350yesyesyesyes
48
This article is protected by copyright. All rights reserved.
Accepted ArticleFigure1.QualityofinnovationaroundtheIPOevent.The?gurepresentschangesinpatentquality,asmeasuredbyScaledCitations,intheyearsaroundtheIPO.Theestimatesandcon?denceintervalsaretakenfromthefollowingspeci?cation:
Yit=β0+
k=5??k=?3k=0
γkEventYeari,k+τi+μt+εi,t.
TheunitofobservationisatthepatentlevelandthedependentvariableisScaledCitations.EventYeari,kisadummyvariableindicatingtherelativeyeararoundtheIPOinwhichapatentapplicationwassubmitted(yearzeroistheyearoftheIPOandtheomittedcategory).Thespeci?cationisestimatedusingOLSandincludes?rm?xede?ects(τi)andyear?xede?ects(μt).Standarderrorsareclusteredatthe?rmlevel.TheestimatesarereportedintheInternetAppendix.
49
This article is protected by copyright. All rights reserved.
正在阅读:
Does Going Public Affect Innovation04-12
如何强化责任提升能力发挥党员先锋模范作用05-12
软件项目实施方案文档(含培训)D03-17
中华人民共和国消防法释义:第五十二条04-20
大学生不良生活习惯11-05
异构网络综述性调研03-08
高考病句题知识汇总、方法及练习(附答案)05-16
嵌入式学习入门,linux基础复习08-08
员工手册确认书12-31
年产68万吨焦化厂硫铵工段的初步设计12-01
- 1Though the definition of the public school is vague
- 2Provable Security for Public Key Schemes
- 3what does she do
- 4unit9 public health
- 5House of Commons Public Administration Select
- 6affect-effect-influence的区别
- 7on public trust to the red cross of society
- 8Student Standardized Testing Does Not Show
- 9英语将来时 be going to
- 10u3_what_are_you_going_to_do
- 计算机试题
- 【2012天津卷高考满分作文】鱼心人不知
- 教育心理学历年真题及答案--浙江教师资格考试
- 20180327-第六届“中金所杯”全国大学生金融知识大赛参考题库
- 洪林兴达煤矿2018年度水情水害预测预报
- 基本要道讲义
- 机电设备安装试运行异常现象分析与对策
- 《有机化学》复习资料-李月明
- 非常可乐非常MC2--非常可乐广告策划提案 - 图文
- 2011中考数学真题解析4 - 科学记数法(含答案)
- 企业人力资源管理师三级07- 09年真题及答案
- 基于单片机的光控自动窗帘控制系统设计说明书1 - 图文
- 20160802神华九江输煤皮带机安装方案001
- (共53套)新人教版一生物必修2(全册)教案汇总 word打印版
- 2014行政管理学总复习
- 中国银监会关于加强地方政府融资平台贷款风险监管的指导意见
- 民宿酒店核心竞争与研究
- 游园活动谜语大全2012
- 河南省天一大联考2016届高三英语5月阶段性测试试题(六)(A卷)
- 小型超市管理系统毕业论文详细设计4
- Innovation
- Public
- Affect
- Going
- Does
- 如何建立域2 - 图文
- 耶鲁大学公开课:古希腊历史简介 第15课 雅典民主(中文版)
- 第三组华为组织分析
- 2017年春季学期苏教版四年级语文下册1.1走,我们去植树同步练习7
- 神经系统监护室护理常规
- 感动校园十大人物2012 - 图文
- 计算机硬件课程设计实验报告
- 校园文化建设汇报材料
- 苏教版科学四年级上册全册教学设计
- 如何对学生进行激励和评价初中英语 - 4
- 2010高考宁夏文综卷 - 政治部分试卷分析
- 最高院环境保护行政案件十大案例
- 浅析幼儿园中游戏教学中的问题及解决对策
- 期刊投稿 地 址和电子邮箱(大全)
- 手工焊和二保焊-焊接缺陷产生原因及防止措施 - 图文
- 计算机存储器 - 内存和外存
- 班主任德育工作个人事迹材料
- 九年级数学上第一二单元检测题
- 模糊C均值聚类算法的C++实现代码
- 高效农业节水灌溉项目可行性研究报告