科拉多·基尼(CorradoGini,1884.5.23-1965.3.13.)，意大利統(tǒng)計學(xué)家、經(jīng)濟學(xué)家和社會學(xué)家，在1922年提出關(guān)于收入分配不平均的一種衡量辦法——基尼系數(shù)(GiniRatio)。

　GiniwasbornintocomfortablecircumstancesinnortheasternItaly.HegraduatedinlawatBolognain1905,withathesisonGenderfromaStatisticalPointofView(published1908).Hisinterestinpublicissueswithamathematicalslant,ratherthaninlawintheusualsense,wasalreadyevident,anditmarkedtherestofhiscareer.Thatcareerwasanenergeticandproductiveone,andextendedoverfieldsoftenthoughtofasseparate.Beforeitwasover,hehadcollectedhonorarydegreesinfourdifferentdisciplines.

　　By1909hewasteachingstatisticsinajuniorpositionatCagliari.Thenextyear,attheageof26,hesucceededtotheChairofStatisticsatthatuniversity.In1912heoccupiedhimselfwiththedescriptivestatisticsofsituationsnotrelatedtothenormaldistribution;inthishepatternswithPareto,whodiscoveredthefirstsignificantnon-normaldistributions.

　　In1913hemovedtoPadua,andin1914publishedabookonthewealthofnations(AdamSmith'sclassictreatiseof1776,whichestablishedeconomicsasaseparatesubjectofinquiry,hadleftsomethingsunsaid,andtheworldhadchanged).In1920hefoundedtheinternationaljournalMetron.In1921,andinanotherjournal,appearedoneofhismostimportantcontributions,aweightythreepagesontheMeasurementofInequalityofIncomes.Alsoin1921hecollectedsomepapersfrom1915-1920underthetitleProblemiSociologicidellaGuerra.

　　Giniwascontinuouslyoccupiedwithquestionsofmeasure,suchasextendingtheconceptofthemeantodistributionshavingnoobviousmean,aswellastheparametersofbivariatedistributions.Fromsuchseeminglysimplematters,hefoundmuchofvaluetocontributetoscience.His1921workontheeconomicanalysisofincomeandwealthhaditscontextinmoregeneralinvestigationsofmeasuresofvariability.

　　Anotherimportantcontributiontoeconomics,specificallyindexnumbertheory,appearedin1924,distinguishingpreviouslyconfusedelementssuchas"pricevariation"and"quantityvariation."In1926,MussolinicreatedanindependentCentralInstituteofStatistics,reportingdirectlytothePremierandresponsibletonogovernmentbureau,toserveastherepositoryandanalyticalcenterforinformationgatheredbythosebureaus.GiniwasmadePresident.In1927hemovedtotheChairofStatisticsatRome.

　　Giniwasagreatcollectorofdata,anddirectedseveralscientificexpeditionsstudyingthedemographicandmedicalprofilesofpopulationsinFezzan,Palestine,Mexico,Poland,Lithuania,and,withinItaly,inCalabriaandSardinia.AsPresidentoftheCentralInstitute,hebecameanorganizerandcentralizerofstatisticalinformationinthetraditionofQuetelet.ButtherewasoppositiontotheInstitute'sstructurefromthevariousbureauswhichwereintendedtobeinpartsubordinatetoit.Mussoliniintervenedinthecontroversy,whichwasresolvedinfavoroftheInstitute'sindependence,butwiththeresultofsouringthepreviouslygoodrelationshipbetweenhimandGini.ThegrowinginterferenceofFascisminintellectualmattersalsodiscouragedcontinuedcloseinvolvementwithgovernment.GiniresignedfromtheInstitutein1932.AnotherenterprisefoundedunderGini'sdirectionin1926,thejournalLaVitaEconomicaItaliana,wasclosedbythegovernmentin1943.

　　Gini'sroundtheclockworkscheduledcontinuedafterthe1932break,asdidhisacademiccareer,hisdevelopmentofpublicationoutletsforstatistics,andhisparticipationinlearnedsocieties.In1932hereceivedanhonorarydegree(ineconomics)fromtheCatholicUniversityofMilan,andin1933becameVicePresidentoftheInternationalSociologicalinstitute.ItalianpolicyunderMussoliniaimedatpopulationincrease;theroleofwomeninthatpolicyasbreeders(fattrici).Ginifollowedanindependentline.NoraFederici,wholatersucceededinestablishingdemographyasafieldapartfromstatistics,tookherdegreeunderhisdirection(inpoliticalscience)atRomein1933.

　　In1934hereceivedanotherhonorarydegree(insociology)fromGeneva,andfoundedthejournalGenusastheprintmediumoftheItalianCommitteefortheStudyofPopulationProblems.In1936,Harvard'stercentennialyear,hereceivedanhonoraryDoctorofSciencedegreefromthatuniversity,andalsofoundedtheFacultyofStatistical,Demographic,andActuarialSciencesatRome,ofwhichheremainedDeanuntil1954.Academichonorslullmany;Gini,theyonlyfurtherenergized.

　　Hisflowofpublications(duringhiscareerthereweremorethan800ofthem)continuedthroughtheseyears,anotableonebeinga1939addresstothefirstmeetingoftheSocietàItalianadiStatistica.ThiswasTheDangersofStatistics,anattackonFisher'sfiduciarymethodsandtheNeyman-Pearsontheoryofhypothesistesting.InthishetookasomewhatBayesianline,arguingfortheimportanceofpriorprobabilitiesinjudgingthemeasuresofasample.Hewasgenerallyimpatientofthetendencytowardpurelymathemeticalelaboration(atraitthatothersbesideshimselfcriticizedinFisherandNeyman),andpreferredamoreconcreteapproach.Applicationswerehisforte.

　　Hismostwidelyknowncontribution,theGiniCoefficient,ishis1921measureoftheinequalityofdistributionofwealth(oranyothervariable).Imagineagraphofcumulativepopulation,summedfromthepoorestupward,andplottedagainstcumulativewealth.Ifallinthatpopulationareequallywealthy,thecumulativecurvewillrisesteadily;itwillinfactbethediagonal(the"45degreeline")ofthechart.Thisrepresentsperfectequalityofwealth;norearrangementcanimproveit.Wemayassignittheinequalityvalue0.Ifonlyonepersonhaswealth,theextremeinequalitysituation,thecumulativewealthcurvewillinsteadfollowthebottomorzerolineofthechartuntilthelastmoment,whenitwillsuddenlyleapupwardto100%.Thatis,itwillfollowtheedgesofthechart,andbetweenitandtheequalitydiagonalwillliehalftheareaoftheentirechart.Wecanassignthissituationthevalueof1,orperfectinequality.

　　Image:Lorentzcurve.gif

　　LorenzCurve(afterWilliamKing)

　　Nowimagineanempiricalcurvedrawnonthatchart,representinganactualcumulativewealthdistribution.ThisistheLorenzcurve.Itwillliesomewherebetweentheaboveextremes.HowshallwemeasurethedegreeofdepartureoftheLorenzcurvefromthe45degreediagonalequalityline?Ifwetaketheareabetweenthecurveandtheequalitydiagonal(thepinkareainthechartabove,representingtheactualdeparturefromequality),anddividethatareabytheareaofhalfthechart(representingthemaximumdeparturefromequality),wewillhaveameasureofthedegreeofinequalityinthatpopulation.Thisratioiscalled(miscalled,sinceitisnotactuallyacoefficient)theGiniCoefficient.Itissimplewhenyouthinkofit,butittookaGinitothinkofit.Itiswidelyusedtodaybygovernmentsandsupervisorybodiesasanindexofwealthinequalityandothervariables.

　　Forcomparisonpurposes,theGnumberfortheUSAin1996wasG=0.456;thefigureforCanadahoveredaroundalessunequal0.300forthatdecade.ItwasconsideredanadvanceinsocialjusticethattheGiniCoefficientforthePhilippineswentfrom0.4881in1997to0.4814in2000,adeclineof1.4%infouryears.

　　TheendofWW2registeredwithGiniasanincreaseintheflowofmajorpublications.Hewroteontheeffectofmigrationsin1946,onstatisticalrelationsandtheirinversionsin1947,onmeasuresoffecundityin1949and1950,onthemeasurementofdifferencesbetweentwopopulationsin1953,andonthewealthofnationsin1956.Allthesewerefurthercontributionstotopicswhichhadengagedhimthroughouthiscareer.Hiscriticismstoodidnotendwithhis1939attackonFisherandNeyman;hechallengedanotherfieldwitha1956paperonDelusionsinEconometrics.Init,hefaultedtheeconometristsforexaggeratingformalaspects,"becauseofthewell-knowndifficultiesofgettingdowntoempiricalbrasstacksineconomics."Noonewhohaschafedatthenumber-flingingoftheeconomists,andtheirremotenessfromeconomicreality,willfailtogiveGinitheirsalute,acrossthedecades.Hehadlongsoughttoincludemorerealityineconomiccomputations.

　　Theconceptofhumancapitalwashis.Hedistinguishedstagesinthegrowthofsocieties,andalsodistinguishednormalfromabnormalprocessesinsocieties,makingthinkablearationalprocessofrestorationforunbalancedsocieties.

　　Hislastmajorworks,in1959,wereontransvariationandonthetransitionfromforcedtofreelaborandtospontaneouslabor.Hisearlyworkonthewealthofnationswasreissuedina2ndeditionin1962.Gini'srecognitionsalsocontinued;hereceivedanhonorarydegree(insocialsciences)fromtheUniversityofCordoba(Argentina)in1963.Totheend,heremainedthecoldandsingle-mindedorganizer,wholivedonlyforhiswork.Hiswifeandtwodaughters,thoughtheyarguablyexisted,impingednotatallonhisprofessionalpersona.Thatsinglenesswasundoubtedlyhismechanismofcontinuity,inacareerspanning,butcontinuingsteadilythrough,twoworldwarsandtheiraftermaths.

　　GiniandToscanini,contemporaries,contributedtoItaly'sstaturefromoppositesidesoftheWW2line,buttheywerecognatepersonalities.ToscaninioncescoldedanorchestrawhichdidnotknowtheBeethovenSeptet,recallinghowinhisearlydayshehadgonewithoutlunchinordertobuythatscore.GiniinsimilarfashiondiscouragedunpreparedstudentswhowantedtodoaPhDwithhim.Hescornedthemodernyouthwhoboughtacar,whereGinihimself,atthatage,"hadboughtacalculator."