Dynamic population model and an application for Leeds - School of 种群动态模型和利兹-应用学院

DynamicpopulationmodelandanapplicationforLeedsSchoolofGeographyUniversityofLeedsOutlineIntroductionApproachesofmodellingsocialsystemsAnapplicationforLeedsModeldescriptionInitialresultanalysisModelimprovementSummaryTounderstand:varioussocialmodellingapproachesindividualbasedmodelsdynamicMSM

howatypicaldynamicMSMisstructuredhowatypicaldynamicMSMworksimportanceofdataforaMSMalternativemodellingapproachesthatmaycomplimentMSMLearningobjectivesSocialSystemsare“messy〞boundarieslargeandcomplex(Moss,2000)ApproachesofmodellingsocialsystemsIndividualBasedModels(IBM):MSM(MicrosimulationModel)CA(CellularAutomata)ABM(AgentBasedModel)ApproachesofmodellingsocialsystemsMSMApproachesofmodellingsocialsystems+t=1,2,…,t=nMSM:StaticvsDynamicApproachesofmodellingsocialsystemsTypeofMSMcharacteristicsAgeingtechniqueEntityInteractivityTimePopulationChangeImpactofprevioussteponthenextStaticDeterministic/StochasticStaticageingNoNotimeelement/stocksofentitiesupdatesNoNoDynamicStochasticDynamicageingPossibleChangeprocessandeventsbuiltinYesYesAdvantagesofStaticMSM:quickertorunsimplertodevelopandunderstandlowercosts:computingresources,skills anddevelopmenttimeoftenwithverydetailedprogrammesimulationsApproachesofmodellingsocialsystemsAdvantagesofDynamicMSM:moredetailsbetterrepresentationofpopulationageing,especiallyinlongterm,asitaccountsinterimchangesineconomicanddemographictrendsgenerallyacceptedmorerealisticrepresentationofmicropopulationunitchangesApproachesofmodellingsocialsystemsMSM:Spatialandnon-SpatialApproachesofmodellingsocialsystems

“Onecannotbeattwoplacesatthesametime.〞 (Hägerstrand,1967) “Meansaretobeemployedsomewhere.〞 (DeMan,1998)

Peoplehavetoliveinalocalareaandtheyareaffectedbylocalenvironment.CAsource:

ABMAnapplicationofLeeds:modellingobjectivesModellingobjectives:TodevelopacompleterepresentationoftheLeedspopulationatafinespatialscaleToproducerich,detailedandrobustforecastsofthefuturepopulationofLeedsToinvestigatescenarioswhichrelatedemographicstoserviceprovisionModellingDescriptionDynamicrepresentationofkeydemographicevents/transactionsinageographicallyidentifiedpopulation

Macrosimulationandmicrosimulationmodels(MSM)arealternativewaysofrealisingtheprocesses(vanImhoffandPost,1998)WeuseaspatialMSMofthepopulationanditsdynamics,butthestructureparallelsthemacromulti-statecohort-component(MSCC)projectionmodelAnMSMdependsongooddataontheimportanttransitionsexperiencedbyindividualsWeexperimentedwithanAgentBasedModel(ABM)forasub-population,students,whereempiricaldataonmigrationhasoftenprovedproblematicWhatdoesthatmean?ScaleLeedspopulation:760,000Eachindividualhasabout60individualvariables+ 20householdvariables+areavariablesVariousprobabilities/rateseg:localisedsingleyearofagebasedmortalityprobabilities

Movement,interactionandbehaviourDistinctivebehavioursfromvariouspopulationgroupsindifferentdemographicprocessesInterdependencyofhouseholdandindividualvariablesindifferentdemographicprocessesDemographicprocessesintheMSM6modularisedprocesses:simpleprocessescomplexprocessesindividualsandhouseholdsInitialResults:LeedspopulationchangeInitialResults:smallareavariationCharacteristicsofstudentmigrantsStudentsarehighlymobileduringtheirstudiesintheuniversitiesMostlyonlymovearoundtheareaclosetotheuniversitieswheretheystudy,NOTinthesuburbanareasMostofthemwillleavethecityoncetheyfinishtheirstudy,NOTgrowingoldinthesuburbanareasDuetothereplenishmentofthestudentpopulationeachyear,thepopulationofthesmallareaswhereuniversitystudentstaytendstoremainyoungerthanotherareasABMAnalternativeapproachthatmodelsindividualsasagentsthroughtheirinteractionswitheachotherandtheenvironmentthattheylivein.Itisveryflexibletointroduceheterogeneousagentswithdistinctivebehavioursthroughtheirbuilt-inrulesItisusefulinmodellingfeaturesofthepopulationwhereknowledgeanddataislacking(Billarietal.,2002).ABMexperiments:StudentMigrantsWerecognisethefollowinggroups:FirstyearundergraduatesOtherundergraduatesMasterstudentsDoctoralstudentsWeapplythefollowinggeneralrules:EachgroupisallowedsetyearstostayintheareaStudentsprefertostaywiththeirfellowstudentsStudentsstayclosetotheiruniversityofstudy,subjecttohousingavailabilityTheydon’t“do〞marriageandfertility

ObservedPredictedComparisonofResults:PureMSM

ComparisonofResults:MSMwithABMObservedPredictedWehavediscussedthedifficultyinmodellingthesocialsystemsandvariousmodellingapproaches.IBMprovidedetailedinfoatindividuallevelandMSMisanimportantsocialmodellingapproach,especiallyinassistingpublicpolicydevelopmentandpl