11 Quantitative methods for comparative constitutional lawcomparativeconstitutionsproject.org/wp-content/uploads/2012_LargeN... · Quantitative methods for comparative constitutional

11

Quantitativemethodsforcomparativeconstitutionallaw

ANNEMEUWESEANDMILAVERSTEEG

1. Introduction

More thantenyearsago,BruceAckermanconsidered,butdismissed,thepossibilityofquantitativeanalysisofconstitutionallaw:

Lookingbroadlyoverthishalfcentury,aretherepatternsthatrepeatthemselvesin thesuccessful establishmentofwrittenconstitutions? Ifso, dodifferentfoundingpatterns shapethesubsequent styleandsubstance ofjudicialreview?At thisstage,therecanbenohopeof rigorouslyquantitativeanswerstosuchquestions.The numberofsuccessstories ismuchtoosmallforstatisticalanalysis;thenumberofvariablesmuchtoolarge.Thereisnowayoutbutanappealtooldfashionedinsight.^

Sincethen, thefield ofcomparative constitutionallawhaschanged. Inrecentyears,anumberofscholarshavebeguntoexploretheapplicabilityofquantitativeor,'largeN'researchmethods toquestionsof comparativeconstitutionallaw.Aspart ofthisenterprise, thesescholarsareturningconstitutionaldocumentsintoquantitativedataandusingthemasobjectsofstatisticalanalysis.Theyareperformingwhatweshallrefertoas'quantitativeconstitutionalcomparison',thesystematiccomparisonofalargenumberofconstitutionalmaterialsthroughtheuseofstatisticalmethods.^Thisemergingsubfield^isthemainfocusofthischapter.

Wewould liketo thankAlecKnight,the editorsof thisvolume, thestudentsfrom thecourseonComparative LawintheTilburgResearchMaster inLawandan anonymousreviewerforhelpfulcommentsandsuggestions.

1 SeeB.Ackerman,'TheRiseofWorldConstitutionalism',VirginiaLawReview,83(1997),771802,773.

2 Cf.D.Law andM.Versteeg,'TheEvolutionandIdeology ofGlobal Constitutionalism',CaliforniaLaw Review,99(2011), 11631259,alsoavailable throughhttp://papers.ssrn.com,p.180(referringtothisapproachas'empiricalconstitutionalstudies').

3 See,e.g.,Z.FlVinsetal.TheEnduranceofNationalConstitutions(CambridgeUniversityPress2009);Z.Elkinsetal,'Baghdad,Tokyo,Kabul...:ConstitutionMakinginOccupied

230

http://papers.ssrn

QUANTITATIVEMETHODS 231

Weshalldiscuss,drawingpartlyonourownexperiences,thepotentialgainsanddrawbacksofquantitativemethodsforcomparativeconstitutional law.Ourcentral claim is that,despitesomedistinctchallenges,quantitativemethodologyhas much tooffer to thecomparative studyofconstitutionallaw.Quantitativemethodologyallowscomparativiststoaddressaseriesofnewquestionsaswellastogeneratenewinsightsintoexistingdebates.Ourcontributionisalsointendedtobepractical.Wediscusssomeofthe

methodologicalchoicesinvolvedincompilingandpreparingquantitativeconstitutionaldata aswell assome ofthe technicalitiesof quantitativedataanalysis.Alongtheway,weintroduceanumberofexamplesofwhatquantitativeconstitutionalcomparisonmaylooklike inpractice.Mostof these illustrations derive from one of theauthors' experiencewithcodingandanalyzingthewrittenconstitutions of188 countriesover a61yeartimeperiod.^Otherillustrationscomefromscholarlyprojectsincomparativepoliticsandrelatedfieldsthatroutinelyemployquantitativemethodology.Inourdiscussion,werecognizethatmostcomparativelawyerslackthe

requiredmethodologicaltoolkittoperformcausalinference.Inresponse

States',WilliamandMaryLawReview,49(2008),113978;T.Ginsburgetal,'CommitmentandDiffusion:How andWhyNationalConstitutions Incorporate International Law',Universityof Illinois LawReview (2008),20138; T.Ginsburg andZ.Elkins, 'AnciUaryPowersofConstitutionalCourts',TexasLawReview,87(2009),1431;B.GoderisandM.Versteeg,'TheTransnationalOriginsofConstitutions:AnEmpiricalInvestigation'(2011),availablethroughhttp://papers.ssrn.com;LawandVersteeg,'TheEvolutionandIdeologyofGlobalConstitutionalism';D.LawandM.Versteeg,'TheDecliningInfluenceoftheUSConstitution'(2011),available throughhttp://papers.ssrn.com.While ourdiscussioninthispaperfocuseson theconstitutionalrealm,we emphasizethat thesamequantitativeapproachisavailabletootherareasoflaw.See,e.g.,M.M.Siems,'NumericalComparativeLaw:DoWeNeedStatisticalEvidenceinLawinOrdertoReduceComplexity?',CardozoJournal of International&Comparative Law,13 (2005),52140 (applyingcomparativemethodstocorporatelaw).Thereisalsoavividandspecificdebateonthelegaloriginsthesisandonthe'DoingBusiness'reportsproducedbytheWorldBank.In2009,theAmericanJournal ofComparative LawhostedaSymposium onthisdebate.See, e.g.,R.Michaels,'ComparativeLawby Numbers?LegalOriginsThesis,DoingBusinessReports, andtheSilenceofTraditionalComparativeLaw',AmericanJournalofComparativeLaw,57(2009),76595;H.Spamann, 'LargeSample,QuantitativeResearch Designs for ComparativeLaw?', AmericanJournal of Comparative Law,57 (2009),797810 (suggesting thatthewiderdebateontheuseofquantitativeanalysisincomparativelawhasbeentaintedbythecontroversyregardingthe'legalorigins'debate).TheWorldBankalsocollectsindicatorsonemployment protectionlaw,bankruptcylaws,access tocredit,propertyregistration,protectionofinvestors,contractenforcementandgoodgovernance.

4 GoderisandVersteeg,'TheTransnationalOriginsofConstitutions:AnEmpiricalInvestigation'(introducingthedataset).

http://papers.ssrn.comhttp://papers.ssrn.com

232 ANNEMEUWESEANDMILA VERSTEEG

tothisconcern,wealso offersuggestionsforcomparativelegalscholarswhowanttoavoidfullblownstatisticalmethods.Wewillshowthat,evenwhenuseddescriptively, quantitativedatamayhavesomethingtooffertothosewithamoreanthropologicalinterestinforeignlegalsystems.Ifnothingelse,scholarsmightusequantitative datatomaptheconstitutionaluniverseandidentifysimilaritiesand differencesacross differentlegalsystems,bysimplysummarizingandcountingquantitativedata.Weorganizetheremainderof thischapterasfollows.Inthenextsec

tion,wediscusshowquantitativecomparativeconstitutionalanalysismaydifferfromquantitativecomparativepoliticalanalysis,whileutilizingtheconsiderableadvancesmade in thelatterfield. Insections 3and4,wesetout thestepsinvolved inbuildingadataset andanalyzing thedata,thetwomainphasesof quantitativeresearch.Section5takesstockandconcludes.

2. Comparativelaw,notpolitics

TheproposedlargeNcomparativeconstitutionallawapproachrelatestoanestablishedtraditionincomparative politicsandpoliticaleconomy.^In thesefields, scholars have long used statisticalmethods to analyzequantitativedata. Today,for almosteverycountry,data existsonelectoralsystemsanddemocratic performance, votingin theUNGeneralAssembly,^andhumanrightspractices,amongmanyothertopics.Thistypeofdataisatthecoreofthecomparativepoliticsandpoliticaleconomytraditions. A seminalwork in the comparative politics traditionthattouches uponconstitutional questionsisArendLijphart'sPatternsofDemocracy,whichanalyzestherelativeperformanceofdifferenttypesofdemocraticinstitutionsinthirtysixcountries.'AmorerecentexamplefromthepoliticaleconomyliteratureisThorstenPerssonandGuidoTabellini'sEconomicEffectsofConstitutions,whichanalyzestheeconomiceffectsofelectoralrules.

5 C.Whytock, 'TakingCausalitySeriouslyin ComparativeConstitutional Latv:Insightsfrom ComparativePolitics andComparative PoliticalEconomy', Loyolaof LosAngelesLawReview,41(2008),629682,636.

6 Seesection3.1infra.7 See, e.g.,E. Voeten, 'Clashesin theAssembly', InternationalOrganization,54 (2000),185215.

8 Seesection3.1infra.9 A.Lijphart,Patterns of Democracy:Government Forms and Performance inThirtySixCountries(YaleUniversityPress.1999).

10 T.PerssonandG.Tabellini'sTheEconomicEffectsofConstitutions(MITPress,2003).


Butmostcomparativelawyersarenotpoliticalscientists.Whilethereismuch thatcomparativelawyerscanlearnfrom thequantitativecomparativepoliticsandpoliticaleconomytraditions,wedonotproposethattheyshouldtakeexactlythesametrack.Inparticular,whatdistinguishestheemergingquantitativecomparativelawapproachfrom comparativepoliticsandpoliticaleconomyisitsfocusonquestionsaboutlawand,inmostcases,itsuseoflegalmaterialsastheobjectofanalysis.Theprovocativetitleoftheirbooknotwithstanding,PerssonandTabellini'sanalysisoftheeconomiceffectsof electoralrules doesnot actuallyconcernthewrittenlegal documentthatmostlawyerswouldtake tobe acountry'sconstitution.Withitsfocuson actualelectoralpractices, thisworkfallswithinthe politicaleconomy traditionmorethan thecomparative lawtraditionenvisionedinthischapter.At thesame time,we dopropose thatlegal scholarsmightconsider

usingthemethodologicaltoolkitfromcomparativepoliticsandpoliticaleconomy.Thistoolkitconsistsofthestatisticalrulesofinferenceasdevelopedinthesocialsciences,whichallowtheresearchertodescribethelaw,engageinsystematiccomparisonsoflegalsystems,and,ifusedproperly,makecausal claimsabout,for instance,theoriginsandeffectivenessoflegal rules.^^ However,conceding thatcausal inferencemaynot alwaysbefeasible,wealsoproposealightversionofquantitativeconstitutionalcomparison,whichmerelyusesdescriptivestatistics.Werecognizethatourproposalmightbesomewhatcontroversial.Many

legalscholarsbelievethatlawhasitsown internallogicandlegalscholarshiphasitsownhighlyvaluedresearchactivity,whichusuallyhaslittletodowithcausalexplanation.Alargepartoflegalscholarship seekstomakevalidlegalclaims,notvalidcausalclaims.'^Moreover,ifanything,legalscholarshipoftenfollowstherulesofpersuasionandadvocacy,nottherulesof inference. Nonetheless,wecontendthatthere areat leastthreereasonstostretchthesedisciplinaryboundaries.First,manylegalscholarsmakecausalclaimsanyway.Forexample,the

fieldof comparativeconstitutionallawispermeatedwithcausalclaims,including,interalia,thefollowingnotions:constitutionsconstraingovernment;judicialreviewprotectshumanrights;socioeconomicrightsare

11 SeeL.EpsteinandG.King,'TheRulesofInference',UniversityofChicagoLawReview,69(2002),1209(providinganintroductiontothesocialsciencerulesofinferencetailoredtoalegalaudience).

12 J.H.MerrymanandR.PerezPerdomo,TheCivil LawTradition:AnIntroduction totheLegalSystems ofEurope and LatinAmerica(Stanford UniversityPress.2007), pp.617(describing'legalscience').

13 EpsteinandKing,'TheRulesofInference',9.

234 ANNEMBUWESEANDMILAVERSTEEG

unenforceable;andconstitutionallawisconverginguponaglobalparadigm.Theseclaims,whichoftentaketheformofunarticulatedassumptions,areessentiallyempirical claims that have largelygone untested.Asonescholarputsit'constitutionalscholarsare...betteratgeneratinghypothesesthanattestingthem'.^^ This,however,doesnotalwaysstoplegalscholarsfrom makingimportantpolicyrecommendations.^^Whilelegalscholarshipmayhave realworld implications,itoftenignores theavailabletoolstotesttheempiricalvalidityofitsclaims.^Second,thefieldfacesanewsetofchallengestowhichtraditionalcom

parativelawmethodologymightbeunabletorespond.Onesuchchallengecomesfrom 'globalization'.'^Globalization,the'clusteroftechnological,economic,andpoliticalinnovationsthathavedrasticallyreducedthebarrierstoeconomic,political,andculturalexchange',' mayhaveaffectedconstitutionallawaroundthe globein anumberof ways.' Globalization'simpact,moreover,isboundtobeglobalinnature.Casestudies,andsmallerscalecomparisons,therefore,areunlikelytofullycapturetheglobalizingnatureofconstitutionalsystemsaroundtheworld.^"Documentingthe impact of globalization on constitutional law, instead, requires

14 D.Law,'Constitutions',inP.CaneandH.Kritzer(eds.).TheOxfordHandbookofEmpiricalLegalResearch(OxfordUniversityPress,2010),pp.37698,390.

15 SeeM.Tushnet,'ThePossibilitiesof ComparativeConstitutional Law', Yale LawJournal,108(1999),12251310,126974(describingthisasanimplicationofthefunctionalapproachtocomparativelaw);M.Tushnet,'SomeReflectionsonMethodinComparativeConstitutionalLaw',inS.Choudhry,TheMigration ofConstitutionalIdeas (CambridgeUniversityPress2007),pp.6783,7374(notingthatfunctionalistslookat'howconstitutionalprovisionsactuallyoperateinrealworldcircumstances'and'drawinferencesaboutgoodconstitutionaldesignfromtheconstitutionalprovisionsthatworkbestaccordingtothefunctionalist'snormativestandards').

16 Werecognize thatothersocialscienceapproaches,suchas casestudies,mayalsoallowresearcherstomakecausalclaimsundercertaincircumstances.Therearevariouswaystoestablishcausality.Theoriginalscientificmethodistoperformrandomizedexperimentsthat allowfor systematiccontrol of alleged causal (independent)variables.However,socialscientists rarelyhave theopportunity toperform experiments.Social scientiststypicallyconsiderstatisticalcontroltobe thesubstituteofchoice.Qualitativemethodssuchas'processtracing'shouldnotbediscarded,certainlynotinasupportingrole.SeeEpsteinandKing,'TheRulesofInference',foradiscussion.

17 H.MuirWatt,'Globalization andComparative Law', inM. Reimannand R.Zimmermann(eds.).TheOxfordHandbookofComparativeLaw(OxfordUniversityPress2006),pp.579607.

18 D.W.Drezner, 'GlobalizationandPolicyConvergence', InternationalStudiesReview,3(2001),5378,53.

19 D.Law,'GlobalizationandtheFutureofConstitutionalRights',NorthwesternUniversityLawReview,102 (2008),12771350, 130742;Law andVersteeg, 'TheEvolution andIdeologyofGlobalConstitutionalism'.

20 SeeMuirWatt,'GlobalizationandComparativeLaw',589.


systematicempiricalexploration,bothovertimeandacrossalargenumberof countries.Another, andpossiblyeven greater,challengefor thefieldis toassessthealleged successesandfailuresof thepastdecadesofwidespreadconstitutionalreforms. Especiallysincethe 1990s,after theend of the cold war, numerouscountriesaround theworld reformedtheirconstitutions,oftenaidedbyconstitutionalexpertsfromtheWest.^'Itseemsplausiblethatsomeconstitutionaldesign choiceshaveyieldedmoresuccess than others.But todatewe have littleempirical insightintowhatworksandwhatdoes not,andwhetherconstitutionsmatterinthefirst place.^^Whatis needed,therefore, isasystematicempiricalexplorationofwhetherconstitutionsmatter,andhowandwhenconstitutionalcommitmentsaffectgovernmentbehavior.^^Whilecasestudiesmightoffervaluablefirstinsightsintothesequestions,quantitativetoolsfrom politicaleconomyandcomparativepoliticshavelongbeenusedtosystematicallyinvestigatetheeffectof differentpolicychoices,lawsandinstitutions.^^Itisthisapproach,wecontend,thatmighthelpshedlightontheallimportantquestionsofwhether,howandwhenconstitutionsmatter.^^Third,thegrowingavailabilityofquantitativelegaldatasetsbringsnew

researchquestionswithinreach.Ofcourse,researchshouldbequestiondrivenratherthandatadriven.However,forcertainresearchquestions,

21 SeeZ.Elkinsetal.TheEnduranceofNationalConstitutions,p.113fig.5.2(documentingaglobalsurgeinthenumberofnewconstitutionscircatheearly1990s);P.Alston,'AFrameworkfortheComparativeAnalysisofBillsofRights',inP.Alston(ed.).PromotingHumanRightsThroughBillsof Rights:ComparativePerspectives(OxfordUniversityPress,1999)p.1(characterizingthe1990sasaperiodof'prolongedconstitutionalfever'inwhich'billsofrightshaveassumedparticularandrenewedimportanceinanextraordinarynumberofcountriesinallpartsoftheworld');M.Versteeg,'TransnationalConstitutionalism',inD. GaUiganandM.Versteeg (eds.).TheSocial andPolitical FoundationsofConstitutions(CambridgeUniversityPress,forthcoming)(conceptualizingforeigninfluencesinconstitutionaldesign).

22 Fora pioneeringworkin thatdirection,seeJ. Gerring,etal,'CentripetalDemocraticGovernance:ATheoryandGlobal Inquiry',The AmericanPolitical ScienceReview,99(2005),56781.

23 Law,'Constitutions',384 (notingthat'theproblemis...thatweknowlittleabout theconditionsunderwhichlargecconstitutionalismsucceeds,inthesenseofdefiningactualpracticeorimprovingsocialwelfare'andthat'themostthatcanbesaidwithconfidenceisthatthereisacontinuing needforacompleteevaluationofthe relationshipbetweenformalconstitutionalprovisionsandconstitutionalpractice').

24 See,e.g.,B.Simmons,MobilizingforHumanRights:InternationalLawinDomesticPolitics(Cambridge University Press, 2009); B. HafnerBurton, 'Justice Lost!The Failure ofInternationalHumanRightsLawtoMatterWhereNeededMost',JournalofPeaceResearch,44(4)(2007),40725.

25 Seeinfrasection4.2.

236 ANNEMEUWESE ANDMILA VERSTEEG

especially those involving a large number of legal systems, 'quantitative methods are the only way to process what would otherwise beoverwhelmingamountsof information from large samples'.^ Quantitativedatasetsalsoofferimportantadvantagesintermsofefficiencyandresearchcooperation.^^Legalscholarstypicallytietheircapacityfornewresearchprojects totheirsubstantiveexpertiseandfamiliaritywith foreignlegalsystems.Thefreeandpublicavailabilityofquantitativedatasetsmeans that it is more feasible toventure into newareas and toworkin teams, in part because replicability is an importantqualitycontrolmechanism.Small research communities often emerge around majordatacollections.^^Admittedly,theimageof the'numbercruncher',whoclaimstobeabletocomputeanythingandeverything,isanegativeone.However,given thecomplexityof thesubject matterand theconstantneedtoadaptthemethodstoservetheaimofansweringquestionsaboutlaw,wedonotthinkthere ismuch riskthatresearcherswhoignorethesubstancewillenterthefieldenmasse?^Thesethree reasonstheomnipresence ofcausal claims,newchal

lengesandthe availabilityofnewdataareinterconnected.Toaddressnewchallengesweneednewdataandareoften requiredtomakecausalclaims.Thetwosubsequentsectionsdiscusstheavailabilityofquantitativeconstitntionaldataandthedifferentwaysinwhichitmightbeusedincomparativeanalysis.

3. Preparatorysteps:buildingadataset

Theuseofquantitativeconstitutionalmethodsrequiresachangeofmindset:scholarsmustuselegalmaterialsas'data'ratherthanas'law.'Whilethisistosomeextenttrueforbothqualitativemethods^"andquantitativemethods,thissectionfocusesonthelatter.Thefirstsubsectiondefinesthe

26 Spamann,'LargeSample,QuantitativeResearchDesignsforComparativeLaw?',799.27 SeeT.GinsburgandT.J.Miles, 'EmpiricismandtheRising IncidenceofCoauthorshipinLaw',UniversityofIllinoisLawReview,101(2011),1785(documentingtheassociationbetweenempiricallegalscholarshipandtheriseofcoauthorship).

28 Asanexample,thereisanemergingscholarlycommunityaroundthe'ComparativeConstitutionsProject'thatisdirected byZacharyElkins,TomGinsburgandJamesMelton.TheComparativeConstitutionsProjectiscurrentlycodingallnationalconstitutionsthathaveever beenwritten. Seewww.comparativeconstitutionsproject.org. Seesection 3.1infraforfurtherdiscussion.

29 SeeMichaels,'ComparativeLawbyNumbers?',767.30 See,e.g.,M.L.Stearns,ConstitutionalProcess:ASocialChoiceAnalysisofSupremeCourt

Decisions(UniversityofMichiganPress,2000).

http://www.comparativeconstitutionsproject.org


objectofanalysisanddiscusseswhattypeofdatatouse,whilethesecondsubsectiondiscusseshowtogoabout'coding'legal textsand preparinglegalmaterialsforstatisticalanalysis.Thesestepsareinterrelatedandtheprocess is an iterative one. It is impossible to identifyan appropriateobjectorunitofanalysiswithoutfirstknowinghowtotreatthedata.Further,whilethefollowingsectionsomitdiscussionsofhowtoformulatearesearchquestion,thisdoesnotmeanthattheuseofquantitativemethodsallowsustodisregardtheissue.Datasetsmaymerelyinspireresearchquestions,orcansometimesrenderfeasibleresearchquestionspreviouslydeemedout ofreach.Their availabilitydoesnotimplythat researcherscan skip thephase of formulatinga problemdriven and theoreticallyinformedresearchquestion.

3.1 Identifyingtheobjectofanalysis

Underourapproach,themostlikelyobjectsofstatisticalanalysisarelegaltexts.Theuseoflegaltextsmayseemobvioustoalegalreadership,giventhattexts, suchas caselaw, statutes,and commentariesareourdefaultobjectofanalysis.Moreover,suchtextstendtobefreelyavailableinlargequantities. For example, full translationsof all of tbeworld'swrittenconstitutionsareavailable fromPeaslee'sConstitutionsofNations^^ andBlaustein and Flanz'sConstitutionsof theCountries of theWorldP Inaddition, foreign judicial decisions are available on LexisNexis and arangeofnonsubscriptiondatabasessuchasWorldLii.^^Someoftheselegaltexts,moreover,havealreadybeentranslated into

quantitativedataandarepubliclyavailableforusebycomparativescholars.Themost ambitiousandcomprehensive dataeffort isarguablythe'Comparative Constitutions Project'. Funded by the National ScienceFoundation,itsleadresearchers,ZacharyElkins,TomGinsburgandJames

31 A.J.Peaslee,ConstitutionsofNations,Istedn,3vols.(TheHague:MartinusNijhof,1950);A.J.Peaslee,ConstitutionsofNations,2ndedn,3vols.(TheHague;MartinusNijhof,1956);A.J.Peaslee,ConstitutionsofNations,3idedn,4wo\s.(TheHague:MartinusNijhof,1965).

32 A. P. Blaustein andG.H. Flanz (eds.).Constitutions of TheCountries of TheWorld(DohhsFerry,NY:OceanaPublications,1971).Thisisacontinuouslyupdatedlooseleafcollectionthatisalsoavailableinelectronicformat.Amorespecializeddatabaseis'WorldConstitutionsIllustrated'.

33 For an overview, seeM.Versteeg, 'Access to Foreign and International Case Law:APractical Guide', prepared for theWest African Judicial Colloquium, Accra, Ghana,810October 2007, www.brandeis.edu/ethics/pdfs/internationaljustice/guidetoforeignjurisprudenceWeb.pdf.


Melton,arecompilingacomprehensivedatabasethatincludesquantitativeinformationoneverynationalconstitutionwrittensince1789.^^Foreach constitution, theyare codingno less than600 variables,onboththe'structural'partoftheconstitutionandthebillofrights.Atthetimeofwriting,this projecthasalready releasedafirst waveofdata,whichcontainscodingofallconstitutionsthatarecurrentlyinforce.^^Theconstitutionalcoding carriedout byone of theauthorsof thischapter issimilarto theComparativeConstitutionsProject. Itcontains 237variablesonconstitutionalrightsandtheirenforcement,from1946to2006.ThisdatawiUalsobepubliclyavailableinthenearfuture.'Written national constitutions are not the only possible objects of

quantitativeconstitutionalinquiry.'^Implementinglegislationandsemiconstitutionaldocuments,orsocalled'superstatutes',''mightalsoserveasobjectsofanalysis.Thesameistruefor judicialdecisions.IntheUS,scholarsarelongfamiliarwiththeSpeathdatabase,which holdsquantitativeinformation oneverydecision theUSSupremeCourt hasever

34 Seesupranote28.35 Atthetime ofwriting,theComparativeConstitutionsProject hasnotyet releasedthehistoricalconstitutionaldata.Thisdatawillbemadeavailableinthenearfuture.

36 Seesupranote4.37 Overthe pastthree decades,a numberof scholarshave madeefforts tocode writtenconstitutions.Mostoftheseprojects,however,codeonlyalimitednumberofvariablesand/orcoveralimitedtimeperiod.See,e.g.,J.BoliBennet,'TheExpansionofNationStates,18701970',Ph.D.Dissertation,StanfordUniversity(1976);H.vanMaarsseveenandG.vanderTang,WrittenConstitutions:AComputerizedComparativeStudy(DobbsFerry, NY:Oceana Publishers, 1978); F. B. Cross, 'TheRelevance of Law in HumanRightsProtection',InternationalReviewofLawandEconomics,19(1999),87;C.Davenport,"'ConstitutionalPromises"andRepressiveReality:ACrossSectionalTimeSeriesInvestigationofWhyPoliticaland CivilLibertiesareSuppressed',Journalof Politics,58(1996),62754;J.FowerakerandT.Landman,CitizenshipRightsandSocialMovements:AComparativeandStatisticalAnalysis(OxfordUniversityPress,1997);L.CampKeith,'ConstitutionalProvisionsforIndividualHumanRights(197696):AreTheyMoreThanMere"WindowDressing"?',PoliticalResearchQuarterly,55(1999),11143;A.BenBassatandM.Dahan,'SocialRightsintheConstitutionandinPractice',JournalofComparativeEconomics,36(2008),10319.A1978studybytwoDutchconstitutionallawprofessors,HenkvanMaarsseveenandGervan derTangstandsoutforthe comprehensiverangeofvariablescoded.Itcovers233variables,onarangeofconstitutionaltopics,includingtheBillofRights.However,thisdataisnottimevarying.Rather,itisacrosssectionofconstitutionsin1978.Bycontrast,the1976studybyJohnBolistandsoutforitscomprehensivetimecoverage,coveringallconstitutionsfrom18701970,althoughnotmovingbeyondthatperiod.

38 SeeW.N.EskridgeandJ.Ferejohn,'SuperStatutes',DukeLawJournal,50(2001),121576,127576.


made.^'Thisdatahasprovidedtheimpetusforawholeliteratureonthedeterminantsof judicialdecisionmaking andthe ideologicalpositionsoftheSupremeCourtjudges.''"Suchanalysisofjudicialdecisionscouldpotentiallybeextendedtotheglobalplane.ArecentandongoinginitiativeistheComparativeConstitutionalCourtProject,whichiscurrentlyassemblingand quantifying thedecisions of thehighest constitutionalcourtsof99countries.'' Itisthistype ofdatathatis attheheart ofthenewcomparativeconstitutionallawtradition.Thoseworking in thesociolegal traditionmayobject toour focus

onlegaltexts:oneofthecoreinsightsfromsociolegalstudies,afterall,isthat lawmust beseen inits socialcontext.AnneliseRiles, forexample,recentlyargued thatcomparative lawscholarshipin thesociolegaltraditionhasactuallymovedaway froma comparisonofdifferentlegaltextsandembraced intensivedialoguewithlegalexpertsfromdifferentlegalsystems.''^ Ourfocuson text inevitablymeans thatwe shallmissoutonsomeoftheintricaciesoflaw'sinteractionwithsociety.Butatthesametime,weareabletocomparealargernumberofcountries,overanextendedperiodoftime.Thistradeoffbetweendepthandbreadthisatthecoreofthesocalled'quantitativequalitativedivide'insocialscientificresearch.''"Atthesametime,ourfocusonconstitutionaltextsdoesnotnecessar

ilymean thatwe have toview lawin isolation.In particular,there aremanysocialsciencedatabasesthatallowustostudylaw'sinteractionwithsociety, albeit through a quantitativelens. Data fromcentralstatistics

39 SeeSpeathDatabase,http://supremecourtdatabase.org/data.php.SeealsoM.Heise,'ThePastPresentandFutureofEmpiricalLegalScholarship;JudicialDecisionMakingandtheNewEmpiricism',Universityof IllinoisLawReview,4 (2002)81950;Spamann,'LargeSample,QuantitativeResearchDesignsforComparativeLaw?',799.

40 See,e.g.,Heise,'ThePast,PresentandFuture'.41 See A. Martin and M. Gabel, 'Collaborative Research: A CrossNational Study ofJudicial Institutionalization and Influence'. See www.nsf.gov/awardsearch/showAward.do?AwardNumber=0751670.

42 SeeA. Riles,'Comparative LawandSocioLegal Studies',inM.ReimannandR.Zimmermann (eds.).The OxfordHandbook ofComparative Law(Oxford UniversityPress,2006), pp. 775814 (describing the'rapprochement' between sociolegalstudies andcomparativelaw).

43 See, e.g., J. A.Casporaso, 'Is therea QuantitativeQualitativeDividein ComparativePolitics?TheCaseofProcessTracing',inT.LandmanandN.Robinson(eds.).TheSageHandbook ofComparative Politics(ThousandOaks,CA:Sage, 2009),p. 67(describingthequantitativequalitativedivideincomparativepolitics).

http://supremecourtdatabase.org/data.php


offices,surveyssuchasthepopular'Eurobarometer',^^performanceindicatorssuch as 'theWorldwideDevelopment Indicators'^^ collected hytheWorld Bank, the 'Database on Political Institutions',^ the 'PolityIV' democracy data,^^ the World Values Survey,^ and some of thedatabasesmentionedabovecanallbeusedtostudylaw'sinteractionwithsociety.^

3.2 Fromtexttodata

Theanalysis of legal texts is at thecoreofanylawyer's activities.Yet,thequantitative analysisof legaldata requiresamentalswitch aswellasa changeinworkingmethods. Legal researcherswillneedtoextractdatafrom,ratherthaninterpret,legaltexts.Whereascreativityandexpertjudgementarekeyqualitieswhenitcomestointerpretation,theextractionofquantitativedatafrom qualitativetextsrequirestheresearcherto

44 TheEurobarometerisaseriesofsurveysregularlyperformedonbehalfoftheEuropeanCommission,whichgeneratesreportsofpublicopinionofcertainissues relatingtotheEuropeanUnion acrossthemember states.Seewtvw.gesis.org/eurobarometer (offeringaccesstoEurobarometerprimarydataforstatisticalanalysis).

45 TheWorldDevelopmentIndicatorsarebeingcollectedbytheWorldBank.Thedatabase,whichincludes datafrom 209countries andcovers theperiod from1960 to2010, isaccessibleathttp://data.worldbank.org/indicator.

46 T.Beck,etal,'NewToolsinComparativePoliticalEconomy:TheDatabaseofPoliticalInstitutions,TheWorldBunkEconomicReview.15(2001),16576.Thisdatabasecontainsabout35yearsofinstitutionaldataforover200countries.

47 SeePolityIVProject:PoliticalRegimeCharacteristicsandTransitions:18002009,www.systemicpeace.org/polity/polity4.htm.Thisdatabasecontainsanimpressive200yearsofdatarelatingtodemocratizationandelectoralcompetitionforover200countries.

48 TheWorldValuesSurvey isa largescale researchproject withan almostglobal reach(90countries),carriedoutbyavastnetworkofsocialscientistscoordinatedbyacentralbody,theWorldValuesSurveyAssociation.Thedata,collectedinwavessince1981,coverspeople'svalues and beliefs, howthey changeover timeand whatsocial andpoliticalimpacttheyhave.Seewww.worldvaluessurvey.org/.For anexampleof (secondary)useofthesedataincomparativeconstitutionallaw,seeLaw,'GlobalizationandtheFutureofConstitutionalRights',13357.

49 Alsoof possibleinterestto comparativelawyersisMarkGibneyetaVs 'PoliticalTerrorScale'thatquantifiesthehumanrightspracticesof188countriesfrom1976onwards.Inparticular,itusestheannualAmnestyInternationalandUSStateDepartmentCountryreportsonhumanrightstoquantifyeverycountry'shumanrightspracticesonafivepointscaleSee www.politicalterrorscale.com.See alsoB.Goderisand M.Versteeg, 'HumanRightsViolationsAfter9/11andtheRoleofConstitutionalConstraints',JournalofLegalStudies(forthcoming,2012).

http://data.worldbank.org/indicatorhttp://www.worldvaluessurvey.org/http://www.politicalterrorscale.com


minimizediscretion,astextmustbetranslatedintonumericalinformationthatotherresearchersmayuse.^In thevast majorityof quantitative research projects, includingthe

emergingfieldofempiricalconstitutionallaw,researchersaccomplishthisthroughcoding, orthe translationof textualproperties intonumericalinformation.Forexample,whenquantifyingnationalconstitutions,theresearchermaydecide toassignavalueof1iftheconstitution containsa prohibition of arbitraryarrest and detention and a value of 0 if itdoesnot.But codingis notalways straightforward.For example,whatif theconstitution contains a right to freedom?Lawyersmaywant toargue thatsuch a right to freedom includesa prohibitionof arbitraryarrest anddetention.This, undoubtedly,wouldmakefor avalid legalargumentincourt.Butwhenquantifyingconstitutionaltexts,therighttofreedomshouldprobablysimplybecodedasarighttofreedom,andnotaprohibitionof arbitraryarrestanddetention.Theexample illustratesthatcodingalways requiresa rangeof decisions tobemade.In ordertoguidesuchdecisions, researchersmustdevelopacodingschemethataccountsfordifferentsituationsandthatshouldbefollowedconsistentlythroughoutthedatacollectionphase.^^Thetranslationoftextintodataisthemainobjectofamethodological

subfieldinthesocialsciences,called'QuantitativeTextAnalysis'(QTA).QTA isa termcoveringa collectionof researchtechniques 'formakinginferencesbysystematicallyandobjectivelyidentifyingspecifiedcharacteristicswithin text'.^^ Most existingQTAbased projectsuse texts thatare peripheral to law, such as political partymanifestos, policy positionpapersornewspaperarticles."ThemesthathavebeentackledusingQTAincludeassessmentofthedeliberativeperformanceofparliaments,"

50 SeeEpstein and King, 'TheRules ofInference', 38 ('Goodempirical work adherestothe replication standard: another researcher should be able to understand, evaluate,build on, and reproduce the research without anyadditional informationfrom theauthor.').

51 See,e.g., Z.Elkins, etal,'TheComparativeConstitutions ProjectCodebook', https://netfiles.uiuc.edu/zelkins/constitutions/files/surveyinstrument.pdf.

52 K.A. Neuendorf,The ContentAnalysis Guidebook (ThousandOaks, CA:Sage, 2002),p.10.QTA isalargesubfieldof 'contentanalysis',afield dedicatedtothequantitativeanalysisof'messages'moregenerally.

53 M. Evans, et al,'Recounting the Courts? ApplyingAutomated Content Analysis toEnhanceEmpiricalLegalResearch',JournalofEmpiricalLegalStudies,4(2007),104157.

54 J.Bara,etal,'AnalysingParliamentaryDebatewithComputerAssistance',SwissPoliticalScienceReview,13(2007),577605.

242 ANNEMEUWESEANDMILA VERSTEEG

positiontakinginEuropeanParliamentspeeches^ând'constitutionalityarguments'incongressionaldebatesaboutabortion.În theremainderofthissection,weshalldiscusssomeoftherecentdevelopmentsinthismethodologicalsubfieldandtheextenttowhichthesemightaidquantitativeconstitutionalcomparison.WithinQTA,themostimportantdistinctionisbetweenautomatedand

nonautomatedcodingschemes.Afamousexampleofanonautomatedcoding scheme is the Comparative Manifestos Project, which used avastteam ofcodersspread overdifferent countriesto handcodemanifestosissued bypoliticalparties,overmorethanhalfa century.^ÂlsotheComparative ConstitutionsProject reliedonhandcodingof alloftheworld'swritten constitutionsbya teamof researchers. Inall thesecases,coderscarefullyreadtheentiredocumentbeforecodingitinaccordancewiththecommoncodebook.Versteeg'sconstitutionscoding,too,reliedonanonautomatedcodingscheme,althoughitdiffersfrom theaforementioned project in thatall codingwas doneby one researcheronly.Codingbymultipleresearchers commonlyleadsto intercoderreUa

bilityproblems.Even whenastrictcodingscheme isinplace,differentresearchersmaymakedifferentcodingdecisions,whichmayleadtounreliabilityofthe data.Ônecommonsolution tothisproblem istohavemoremultiplecoderscodethesametextandchecktheircodingagainsteachother.TheComparativeConstitutionsProject,forexample,hasallconstitutionaltextscodedby twocoders,whiledisagreementsare adjudicatedbytheprincipalinvestigators.Butinpartbecauseofintercoderreliabilityconcerns,QTAresearchershavestartedtodevelopautomated

55 S. Proksch and J. Slapin, 'Position Taking in European Parliament Speeches', BritishJournalofPoliticalScience,40(2009),587611.

56 C.SchonhardtBailey,'TheCongressionalDebateonPartialBirthAbortion:ConstitutionalGravitas andMoral Passion',BritishJournal ofPolitical Science,38(2008), 383410.

57 The ComparativeManifestos Project has collected data from political parties' electionprogrammes frommore than50 countriescovering allfree,democratic electionssince1945.Thedataandcodebooksareavailablethroughhttp://manifestoproject.wzb.eu/.

58 TheComparativeConstitutionsProjectreliesonmultiplecoders,thoughitsintercoderreliabilitymeasuresseemimpressivelyhigh.See,www.comparativeconstitutionsproject.org/reliability.htm.TheComparativeManifestosProject,ontheotherhand,hasreceivedsomecriticisminthisrespect.See,S.Mikhaylov,M.LaverandK.Benoit,'CoderReliabilityandMisclassificationinComparativeManifestoProjectCodings',Paperpresentedatthe66thMPSAAnnual NationalConference,PalmerHouseHiltonHotelandTowers,36April2008.

http://manifestoproject.wzbhttp://www.comparativeconstitutionsproject


codingproceduresthatminimizecoderdiscretionevenfurther.Thekeyfeatureof automatedcodingis thattexts arenotquantifiedbya teamof researchersbutbysearch engines that relyon somepredeterminedalgorithm.Automatedcodingschemes,allegedly,scoremuchbetter oncoremethodologicalconcerns,suchasintercoderagreement,reliability,validation,accuracyandprecision.^But limiting coder discretion may come at a price. Legal scholars

undoubtedlywonderwhethersearch engineswillbeable todetect relevanttextualnuances.Forexample,ifacomputerisinstructedtodetecta'prohibitionofarbitraryarrestanddetention'andtheconstitutionstatesthatthe'governmentshallregulatearrestanddetention',itssearchenginehasto heable torecognize that thesemay notbethesame thing.Yet,someoftheautomatedcodingproceduresallowformorediscretionandflexibilitythanothers."Someof theseproceduresaredictionarybased,whichmeansthesoftware usesa listof wordsor termscompiledespeciallyfor theproject bytheresearcheror triedand testedbya researchteam.' Other approaches, by contrast, are nondictionary based andalmostexclusivelyrelyonstatistics,usingpropertiessuchaswordfrequencydistributionsof'referencetexts'thathavebeenverifiedbyexpertstocomeupwithestimationson thebasisof socalled'virgintexts' thatarebeing'read'bythecomputeronly.^Putdifferently,thewordsarethedata.Thisdevelopment illustrates howresearcherscan take 'text asdata'

to the extreme. For most legal researchers, the reductionist effectsof nondictionary approaches will probably outweigh its advantagesin minimizingdiscretion.Adapting methodsso thatmeaningful legaldifferencesaretakenintoaccountmaytakealotofadditionalinvestment

59 S.Mikhaylov, etal,'CoderReliabilityandMisclassification inComparativeManifestoProjectCodings', Paperpresented atthe NationalConference oftheMidwestPoliticalScienceAssociation,Chicago,36April 2008,http://citation.allacademic.com/meta/p_mlaapa_research_citation/2/6/5/7/l/pages265710/p265710l.php.

60 See,www.contentanalysis.de/software/quantitativeanalysis (providing links tomanyautomatedcodingschemes).Researcherswhoemphasizethepracticalaidthatcomputerscanofferinprocessinglargeamountsoftext,ratherthantheadditionalstatisticalpower,oftencalltheapproachComputerAidedTextAnalysis(CATA).

61 Afurther distinction can bemade betweenmethodsand programmes relyingon aninternaldictionary(e.g.Alceste) oranexternaldictionarycompiledby theresearchers(e.g.Hamlet).

62 See,e.g., K.Benoit, S.Mikhaylov andM. Laver, 'TreatingWords asDatawith Error:UncertaintyinTextStatementsofPolicyPositions',AmericanJournalofPoliticalScience,53(2009),495513.

244 ANNEMEUWESE ANDMILAVERSTEEG

ineach researchphase.In itscurrentstateofdevelopment,notallQTAmethodsseemsuitable forlargescale useinquantitativeconstitutionalcomparison.However,therearereasonswhyQTAmaynonethelessbeofinterest.First,QTAmaybepartofa 'mixedmethods'designinwhichitmayserve,forinstance,toconfirm trendsthatwerediscovered throughqualitativeresearch.^Second,therearesomeinterestingrecentdevelopmentsthatcombinethestrengthsofdifferentQTAapproachestoproducetechniquesthatmaybeofinterest tothecomparative lawyer.Inparticular,newsoftware isbeingdeveloped that iscapableof 'reading'largeamountsoftext inanylanguage.Such softwarecould pioneerworkonlegalsystemswhereEnglishtranslationsoflegaldocumentsarescarce.^Third,automatedQTAmaybringimportantbenefitsintermsofthetimeandresources requiredtocollectone'sdata.Whilecoding constitutionsfor188 countriesover a60year timeperiod tookabout 12monthsoffulltimeworktocomplete, acomputermightbe abletodo thisinlessthanaday.Atthesametime,theamountoftimesavedmaybesomewhatdeceptive,sinceautomatedcodingapproachesrequirethetextstobepreparedand presentedin acertainencoding format.Moreover, acertainlevelof technologicalinsightandtrainingis neededto usemost ofthesoftwarerequiredforautomatedcoding.^

63 Foranintroductionto'mixedmethods'researchdesignssee,e.g.,R.B.JohnsonandA.J. Onwuegbuzie, 'MixedMethods Research: A Research ParadigmWhoseTime HasCome', Educational Researcher, 33 (2004), 1426. An example of an application ofQTA as part of a mixedmethods' design outside of thefield of comparativelaw isJ. ScourfieldMcLauchlan,Congressional Participation asAmicus Curiaebeforethe USSupremeCourt(NewYork:LFBScholarlyPublishing,2005).Thisworkisalsoanexampleof howquantitative text analysiscan pavethe wayfor theanalysis of newdocumentcategories (amicuscuriae briefsin thiscase).See infira section 4.2for afurtherdiscussion.

64 See,e.g.,CATPAC,www.galileoco.com/N.catpac.asp.Thissoftwarecanbeusedtosummarizetexts butalso producesavarietyofoutputssuch asword andalphabetical frequencies.Italsouncoverspatternsofworduseandperformsclusteranalysis.AnexampleofanapplicationisJ.W.PennebakerandC.K.Chung,'ComputerizedTextAnalysisofalQaedaTranscripts', inK. KrippendorfandM.A.Bock (eds.).TheContentAnalysisReader(Sage, 2008)wherepropertiesasopposedto meaningoftexts areused todeterminesafetyperceptionsof terroristorganizations. Forsimpler but'open licence'software,seewww.yoshikoder.org/(allowingformultilingualanalysis,albeitwithmanylimitations).

65 TheannualsummerschooloftheEuropeanConsortiumforPoliticalResearch (ECPR)inLjubljanahasbeenofferingcoursesonQuantitativeTextAnalysisinthepastfewyears.Seevww.ecprnet.eu/methods^chools/summerschools/Ljubljana/.

http://www.galileoco.com/N.catpac.asp


4. Whatnext?Quantitativecomparisonsusingstatistics

Havingdiscussedthedifferentapproachestocollectingquantitativelegalmaterials,weshall nextdiscuss theuses forsuchdata.Wewillbebrief,as this chapter is not the right forum for an introduction in statisticalmethods.Whilewethinkthatanylawyercontemplatingthis typeofquantitativecomparisonwouldbewelladvisedtotakeastatisticscourse,weemphasizethatabundanttechnicalskillsarenotnecessarytoanalyzequantitativedataforthepurposeofdescriptioninconstitutionalcomparison.Inparticular,weenvisiontwodifferentwaysinwhichcomparativistsmayusequantitativedata,oneofwhichismoreambitious,andrequiresmorestatistical skills, than theother.First, comparative lawyers coulduse thequantitative datato simplydescribe andmaplegal similaritiesanddifferencesacrosslegalsystems.Theycouldusedescriptivestatisticstocompareandmaptrends,withoutmakinganycausalclaims.Second,comparativelawyerscouldusestatisticaltools,inparticularmultivariateregressionanalysis,totestcausalexplanations.Thefirstallowsustomapsomegeneraltrendsintheglobalconstitutionallandscape,whilethesecondallowsusto,atleastundersomeconditions,turntomoreambitiousquestions,suchaswhetherconstitutionsmatter.Theremainderofthissectionwilldiscusseachofthoseapproachesinturn.

4.1 Mappingconstitutionaltrends

Withnewempiricaldata,showingtrendsandmappingsimilaritiesanddissimilaritiesmightbeofinterestinitself.Withsimpledescriptivetools,wecan addresswhat,according toDavid Kennedy,constitutes thefirstmethodologicalstepofanycomparativelawenquiry:'identify[ing]interestingdifferences andsimilarities amonglegal phenomenain differentlegalregimes'.'' Butunlike thetraditionalcomparativelawenquiry,thenewempiricaldataallowsus tocomparemorecountriesinamoresystematicmanner.Aftercodingrightsvariablesfromconstitutionaltexts,wecananalyze

theconstitutionalprevalenceofcivilandpoliticalrights,forexample.An

66 See,e.g.,F.Schauer,'ComparativeConstitutionalCompliance:NotestowardsaResearchAgenda',chapter10inthisvolume.

67 D.Kennedy,'ThePoliticsandMethodsofComparativeLaw',inM.BussaniandU.Mattei(eds.).TheCommonCoreofEuropeanPrivateLaw(TheHague:KluwerLawInternational,2003),pp.131208,140.

246 ANNEMEUWBSE ANDMILAVERSTEEG

* I

year

Figure1.

intuitivewaytodoso istodrawagraph thatplotstheaverage numberofrightsperconstitutionovertime.Figure1depictstheaveragenumberofcivilandpoliticalrightsperconstitutionovertime,outofatotalof31possiblerightsinthiscategory.However,overallaveragesmayconcealdifferenttrends.Therefore,to

getasenseofthedifferencesacrossdifferentcountries,wecandrawasetofworldmapsthat graphicallydisplay thenumber of rightsin eachof

68 Thisgraphisbasedonthefollowingrights:(1)therighttovote,(2)therighttoassembly,(3) the right to association, (4) the right to form political parties, (5) the right toinformationabout thegovernment, (6) theright topetition, (7) theright toamparo,(8)therighttoresist,(9)therighttoaremedy, (10)therighttocompensation,(11)therighttolife,(12)theprohibitionofthedeathpenalty,(13)therighttolifefortheunborn,(14)the prohibitionof torture,(15) theprohibitionofslavery, (16)the prohibitionofarbitraryarrests anddetention, (17) thefreedom ofmovement, (18) thefreedom todevelopone'spersonality, (19)theright tobeararms, (20)the rightnot tobeexpelledfrom one'shome territory, (21) thefreedom ofeducation, (22) theright toestablishschools,(23) therighttoartisticfreedom, (24)the righttoprivacyoftheperson, (25)therighttoprivacyofthehome,(26)therighttoprivacyofpersonaldata,(27)therighttoprivacyoffamilylife,(28)therighttoprivacyofcommunication,(29)thefreedomofreligion,(30)thefreedomofexpressionand(31)thefreedomofthepress.

69 SeeT.WonnacottandR.Wonnacott,IntroductoryStatistics,5thedn (NewYork:Wiley,1990),p.1(introducingthevarioustypesofavailabledescriptivestatistics).

CivilandPoliticalRightsin2006

Figure2c.

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theworld'sconstitutions.Withasimplemappingprogram,available inmoststandardstatisticssoftwarepackages,wecan depictconstitutionalfeaturesonaworldmap.^ Figures2acdepictthenumberofrightsperconstitutionin1946,1976and2006,respectively.Theycanbeviewedasglobalsnapshotsofthenumberofconstitutionalrightsandprovidethereaderwithanintuitivetooltosystematicallycomparealargenumberofcountries.Inthesamevein,wecanusedescriptivetoolstostudythedevelopment

ofoneparticularrightonly.Forexample.Figure3depictsthepercentageof constitutionsthat contain a prohibitionof torture.^^ Similargraphscouldbedrawnforotherrights,orperhapsforgroupsofrights.Thesegraphsandmapsmaybeinsightfulintheirownright.Figure1,

for example, strongly suggests that constitutions have become morerightsinclusiveover time.In 1946, theaverageconstitution contained10outofthe31civilandpoliticalrightsprovisions.Bycontrast,in2006,theaverageconstitutioncontained17outofthe31rightsprovisions,an

70 Thesemapsareeasytogeneratewiththe'spmap'programme inStata.SeeF. Huebler,'Guide to Creating Maps with Stata', http://huebler.blogspot.eom/2005/ll/creatingmapswithstata.html.

71 LawandVersteeg,'TheDecliningInfluenceoftheUSConstitution'(2011).


increaseofmorethan70percent.Thesametrend isapparentfrom thechangingcolorschemeontheworldmaps.Basedonthiskindofdescriptivetools,theresearchermightconcludethatsometrendsmayormaynotbeconsistentwithaparticularhypothesis.Forexample,thegrowingpopularityofcivilandpoliticalrightsisconsistentwith thehypothesisthatdemocratizationandcivilandpoliticalrightsdevelophandinhand.Afterall,thepast decadesnotonlywitnessedagrowingpopularityof constitutionalrights,butalsodifferent'waves'ofdemocratization.'^^Similarly,thesametrendisconsistentwiththehypothesisthatconstitutionalrightsdevelopedin symbiosiswith theinternationalhuman rightsregime, asinternationalhumanrightstreatiesproliferatedinthesameperiod.But,importantly,fromthesetrends,wecannotinferthatbecauseoftheinternationalhumanrightsregime,orbecauseofdemocratization,constitutionalrightsgainedinpopularity.Thesearecausalclaims,anddescriptivestatisticsalonedonotsupportsuchclaims.Descriptioncanmerelybeusedtoshowlegaldevelopmentsacrosstimeandspace,nottomakeanyclaimsastothecausesofthesedevelopments.^^Evenwiththeselimitationsinmind,descriptivetoolsmaybeofvalue,

asthedevelopmentofmapsandtaxonomieshaslongbeenacoreactivityofcomparative lawyers.Theymight,moreover,beused tocomplementmoreethnographiccomparative lawscholarship, ina'mixedmethods'approach.Today,comparativeconstitutionallawismainly thefieldofthecountrystudy,wherescholarsperformasmall numberof indepthcasestudies andset forthhypothesesand theoriesbased onthese casestudies.''Quantitativedatacancomplementthesestudies.Inparticular,thecomparativeresearchermaywanttomapsomegeneraltrendsbeforemovingtoasmaller numberof casestudies. Forexample, a researcherwriting on socioeconomic rights may download the socioeconomicrightsdata from theComparativeConstitutions Project toshow somegeneraltrendsinthedevelopmentofsocioeconomicrights.Aftersuchanintroduction,heorshemayzoominononeormorecasestudies,like

72 S.Huntington,TheThirdWave:DemocratizationintheLate20thCentury(UniversityofOklahomaPress,1991).

73 See,e.g.,B.Simmons,MobilizingforHumanRights(showingthestrongproliferationofhumanrightstreatiesinthepostWWIIperiod).

74 EpsteinandKing,'TheRules ofInference', 9 (noting,after reviewingall theempiricalpapersinthemajorlawreviews, that'[t]oomuchlegalscholarshipignoresthe rulesofinferenceandappliesinsteadthe"rules"ofpersuasionandadvocacy.).

75 Seesupranote63.76 M.Tushnet,'TheContinuingSignificanceof"CountryStudies"inComparativeConstitutionalLaw'(Manuscript2011).

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SouthAfrica andIndia.Someofthe leadingworks inthe comparativeconstitutionallawliteraturealreadyfollowthis approach.For example,theintroductorychapterofTomGinsburg'sConstitutionalCourtsinNewDemocraciesshows some general trends on constitutional courts andjudicialreview,beforemovingtoasmallnumberofcasestudiesinEastAsia.^^ DavidErdosfollows asimilarstrategy inhisDelegatingBills ofRights?^Simpledescriptivestatisticswouldaidsuchanalyses.Quantitative data could,moreover, aid theselection of cases.After

lookingatglobaltrends,the researchermaywanttopickaconstitutionthat is in linewith global trends, for example.^^ It is with this kindofapplications thatthe newquantitative data,combined withsimpledescriptivetools,maybevaluableforcomparativistswithoutanappetiteforstatisticalwork.

4.2 Causalinference

Intheprevioussubsection,weillustrated howdescriptivestatisticsmaybeusedtoanalyzequantitativelegaldata.Somecomparativelawyersmaywant to stop there, either because theyare unfamiliarwith themoresophisticatedstatisticalmethodsorbecausetheyareuninterestedinaskingcausalquestions.Forthosewhowanttomovebeyonddescriptionandillustration,thissubsectiondiscussesthepossibilityofusingquantitativeconstitutionaldatafor thepurposeofcausalinference.To returntotheexamplefromtheprevioussubsection:onthebasisofthedataunderlyingthegraphicspresentedintheprevioussubsectiontheresearchermaymerelyconcludethattheproliferationofcivilandpoliticalrights isconsistentwiththehypothesisthatdemocratizationproducesmorerights.Inordertomake theclaimthattheserightsbecomemorepopular becauseofdemocratization,heorshewould needtousemultivariateregressionanalysis.With regression analysis, the researcher can isolate the effectofdemocracyonconstitutional rightsfromother possibleexplanationsforconstitutionalrightsadoption.Thus,regressionanalysisallowsustoexamine theeffect of democracyon constitutional rights,whileholdingconstantotherfactorsthatmayaffectconstitutionalrightsadoption,

77 T. Ginsburg, Judicial Review in New Democracies: Constitutional Courts in East Asia(CambridgeUniversityPress,2003).

78 D.Erdos,DelegatingRights(OxfordUniversityPress,2010).79 See R.Hirschl,'The Question ofCase Selection in ComparativeConstitutionalLaw',AmericanJournal of Comparative Law,53 (2005), 12555 (providinga discussion ofdifferentmethodsofcaseselection).


suchasa country'sactualhuman rightsrecordoritslevel ofeconomicdevelopment.Thisisnottherightplace toofferanintroductiontoregressionanal

ysis.We referto thebasictextbooks instatisticsfor that.Butwewanttoemphasizethewiderangeofpossibilitiesthatareofferedbyregressionanalysis.Notonlycanwestudythedeterminantsofconstitutionalrights,suchasdemocracyoreconomicdevelopment,butwecanalsoassesstheimpactof constitutionaldesignchoicesondifferentoutcomevariables.Forexample,wecouldexaminewhethertheadoptionofaconstitutionalprohibitionoftorturereducesincidentsoftorture,orwhethertheadoptionofaconstitutionalrighttoeducationincreasesgovernmentspendingoneducation.Or,inmoretechnicallanguage,wecanuseconstitutionaldatabothasa dependent(oroutcome)variable andas the independent(orexplanatory)variable.Butsomecautionaryremarksareinorder.Evenwhereregressionanal

ysisrevealsstatisticallysignificantrelationships,itdoesnotautomaticallymeanthatthesearealsocausalrelationships.Inthisrespect,itisimportant to distinguish between the concepts of correlationand causation.If twovariables arecorrelated, thissimplymeans thattheyarerelated.Forexample,the regressionmodelmay revealastatisticallysignificantrelationshipbetweendemocracyandconstitutionalrightsadoption,evenaftercontrollingforactualhuman rightspracticesandeconomicdevelopment.Inthiscase,democracyandconstitutionalrightsarecorrelated:whenthereismoredemocracy,therearealsomorerights.Butinordertomakethecausal claimthat becauseofdemocracycountriesadoptmorerights,wewouldhavetocarefullyconsideranumberofadditionalfactors.First, wewould have to consider the possibility thatmore democ

racydoesnotleadto constitutionalrights,butthatmoreconstitutionalrightslead tomoredemocracy instead.In econometrics, thisis calledthe 'reversed causality problem'.One famousexample of the reversedcausalityproblemistherelationshipbetweenpolicepresenceandviolentcrimes.' These factors are correlated,such thatwhen there aremorepolice,there ismorecrime.Butshould weconclude thatbecauseof the

80 SeeM.Verbeek, AGuide to Modern Econometrics (Chichester, UK:Wiley, 2000); J.Wooldridge,IntroductoryEconometrics:AModernApproach(Mason,OH:SouthWesternCollegePublications, 2007).For moreadvanced treatments,see alsoW. Greene(ed.).EconometricAnalysis,6thedn(UpperSaddleRiver,NJ:Pearson PrenticeHall,2007);J.Wooldridge,EconometricAnalysisofCrossSectionandPanelData(MITPress,2010).

81 S. Levitt, 'UsingElectoral Cycles in PoliceHiringto Estimate theEffect of Police onCrime',AmericanEconomicReview,87(1997),27090.

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police,crimeincreases?Orshouldweinsteadconcludethatbecauseofhighcrimerates,policepresenceincreases?Commonsensetellsusthatthelatterismorelikelytobetrue.Attheminimum,researchersshouldaddressandconceptualizethecausalityquestionandexplainwhytheythinkthatcausalityrunsonewayandnot theother.Thesocialscienceshave alsodevelopedmoresophisticatedmethodstoaddressthereversedcausalityproblem,themostcommonofwhichistheuseofinstrumentalvariables'.'Instrumentalvariables'exploitan exogenoussourceofvariation intheindependentvariablethatdoesnotaffect thedependentvariable,otherthan through theindependent variable.For example,one wellknownstudyineconomicsusessettlermortalityasan'instrument'toestablishthecausal effect of institutionsoneconomicgrowth.^ Anotherstudyusesrainfalltoestablishtheeffectofeconomicgrowthoncivilwar.'Werefer tootherwritersfor afull treatmentof theinstrumental variablesapproach.^Second,wewould have to considerwhether there areother factors

thatare omittedfrom theregression modeland thatmight affectbothdemocracyandconstitutionalrights.GDPpercapita,forexample,mightaffect bothdemocracyand rights:when countriesbecome richer theybecomemoredemocraticandadoptmorerights.Inthiscase,thecorrelationbetweenrightsanddemocracyisaspuriousone:itisGDPpercapitathatistherealdeterminantofbothdemocracyandrights.Ineconometrics,this iscalled the'omittedvariablebiasproblem'.Thisproblemcanbesolved throughinclusion ofthepossiblecompetingexplanationsforrightsadoptionthatarealsocorrelatedwithdemocracy.IfGDPconstitutessuchacompetingexplanation,theomittedvariablebiasproblemissolvedthroughtheinclusionofavariablethatcapturesGDPpercapita.Themainproblem,however,isthatnotallpossiblecompetingexplanationsof rightsadoption areobservable andquantifiable. Itmaybe thecase,for example, thatsomethinglike a'rights culture',or 'rightsconsciousness',affectsboth democracyand constitutionalrights adoption.In thiscase, itwould behardertosolvethe omittedvariable problem,as quantitativeinformation ondifferent 'rightscultures'might notbe

82 See,e.g.,D.Acemoglu,etal,"TheColonialOriginsofComparativeDevelopment:AnEmpiricallnvestigation',AmericanficonomicReview,91(2001),13691401(usingsettlermortalityasaninstrumentforinstitutionalquality).

83 E. Miquel et al,'Economic Shocks and Civil Conflict: An Instrumental VariablesApproach',JournalofPolitical Economy,112(2004),72553(usingrainfallasaninstrumentforeconomicgrowth).

84 See,e.g., J.D.Angrist andJ. S.Pischke, MostlyHarmless Econometrics:AnEmpiricistsCompanion(PrincetonUniversityPress,2009).


available.Again,thereexistanumberofmoretechnicalsolutionstodealwithomittedvariablebias.'Instrumental variableanalysis',mentionedabove,isoneofthem.Anothercommonlyemployedmethodis theuseof'fixedeffects',whichmaximizetheexplanatorypoweroftheregressionmodelbecausetheycontrolforall thingswithina countrythatremainconstantovertime.Thus,totheextenta'rightsculture'doesnotchangeovertime,itwillhecapturedbythecountry'sfixedeffects.Quantitative research does not alwaysmanage to solve theomitted

variable bias problem.But at theminimum, researchers should thinklongand hardabout alternativestories andtry tocontrolfor thembyaddingimportant competingexplanations to the regressionmodel.Incaseit turnsout tobe impossibleto accountfor aplausible alternativeexplanation,theresearchershouldprobablybeupfrontaboutthis.Heorshemayhaveto concedethatdemocracyseemsto affectconstitutionalrights,butthatdemocracymightactuallybeaproxyforsomethingmorefundamentalandfarlesstangible,likearightsculture.Werealizethatwearenowventuringintounknownterritoryformost

legalresearchers.Yet,wedothinkthatitisimportant toemphasizethatregressionanalysis,whichisessentialtomakecausalclaims,comeswithitsown distinctset ofmethodologicalchallenges. Althoughwe believethatregressionanalysismightbeapromisingavenueforcomparativelaw,ahealthydoseofskepticismshouldalwaysbeappliedtocausalclaims.

5. Conclusion

Fromourdiscussion,ithasbecomeapparentthatquantitativecomparative(constitutional)lawismoreorlessdiametricallyopposedtothelongestablishedcomparativelawtraditionthatviewscomparisonasa'wayoflife'.^Accordingtothistradition,toknowthelawsofFrance,forexample,theresearchermustspeakandreadFrench,liveinFranceforawhile,andknowthesentimentsof Frenchmen.Only thencan the researchercomparethelawsofFrancewiththoseofhisorherowncountry.Thesortofcomparisonweproposeinthischapterisverydifferentandconstitutesanewmethodologicalfrontierforcomparative(constitutional)law.

85 D.Kennedy,'TheMethodsandthePoliticsinComparativeLegalStudies:TraditionsandTransitions'inP. LegrandandR.Monday(eds.),ComparativeLegal Studies:TraditionsandTransitions(CambridgeUniversityPress,2003),pp.345436,351(quotingWilliamTwining).

86 J. Gerring, Social ScienceMethodology:ACriterial Framework (CambridgeUniversityPress,2001).p.157;Spamann,'LargeSample,QuantitativeResearchDesignsforComparativeLaw?'.

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At thesame time,quantitative research designsfit remarkablywellwithin thedisciplinarymould of comparative lawand could produceinsightsthatareusablebeyondthequantitativesubfield.EachofthefourstepsthatDavidKennedyonceidentifiedastakingplaceinalmosteverycomparativelawenquirycanbetackled inquantitativeprojectsaswell.First,'identify interestingdifferencesandsimilaritiesamong legalphenomenaindifferentlegalregimes'.Second,'wheretherearesimilarities,dealwiththe"transplant"hypothesis'.^Third,'allocate thesimilaritiesanddifferenceswhichremainvariouslytoculturalandtechnicalfactors.Fourth,'generateaplausiblecausalaccountofwhatyouhavemapped'.Wedonot suggestthatquantitativeanalysis istheonlywaytoestablishcausality.Indepthcasestudiesandprocesstracingalsoallowresearcherstotakeupcausalquestions.However,thewayinwhichquantitativeanalysisestablishescausalitymaymeetapressingneedincomparativeconstitutionalscholarship.Since someof themost pressingquestions inthisfieldrequireustolookatglobalconstitutionaltrendsandinvolvehighlyirregularcausalrelationships,quantitativeanalysishasasignificantcontributiontomake.'First,quantitativemethodsmayhelpcomparative constitutionallaw

scholarshipconnect tolarge interdisciplinaryprojects inwhich,in thewordsof RalfMichaels, comparativelawhasbeen largely 'silent'.'" Inorderto ensurethat comparativelawasafield doesnot lose relevancetohighimpact research,itneedstobringits expertisetobear ontheseprojects.Forexample,theWorldValuesSurvey'^questionnairedoescontainquestionsonpeople'sperceptionsoffundamental rightsprotectionin their countries,but hadcomparative lawyersbeen partof theteamdrawingup thequestionnaire thesecould havebeen morerefined andbettertailoredtoour researchneeds.Forinstance,questionsonknowledgeandperceptionsoflawandlegalinstitutionscouldbehighlyrelevanttocomparativelawresearch.Second,our experiencesprovideprima facieevidencein supportof

'mixed methods'.Quantitative constitutional comparison and empiricalcomparativelawgenerallymust'ultimatelybeconfined towhatcan

87 AsanexampleofhowquantitativeresearchcanbeusedtotestthetransplanthypothesisseeGoderisand Versteeg,'The TransnationalOrigins ofConstitutions;An EmpiricalInvestigation'.

88 Kennedy,'TheMethodsandthePoliticsinComparativeLegalStudies',35669.89 Cerring,SocialScienceMethodology,p.169.90 Michaels,'ComparativeLawbyNumbers?',767. 91 Seesupranote48.


bemeasured'and, therefore, 'cannotcapture thefull richnessof legalsystems'.^However,asMichaelssuggests,thereductionistnatureofthesemethodsisnoreasontodiscardthem,onlytoensuretheyarenotappliedinisolation.'^Or, inthewordsofReitz,'[cjomparativelawneedsallthehelpitcanget'."'Wellexecutedresearchdesigns,relyingonthequantitativeanalysisoflegalorsemilegaltextsorusingsurveyorindictorbaseddata,eitherastheleadmethodinlargecooperativeprojectsorinaclearlydefinedsupportrole,aregoodcandidatestooffersuchhelptocomparativelaw.

92 Michaels,'ComparativeLawbyNumbers?',778. 93 Ibid.94 J.Reitz, 'LegalOrigins,ComparativeLaw, andPolitical Economy',American JournalofComparativeLaw,57(2009),84762,851.

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