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

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Centre for Compuational Geography,Dynamic population model and an application for Leeds,School of Geography,University of Leeds,Outline,Introduction,Approaches of modelling social systems,An application for Leeds,Model description,Initial result analysis,Model improvement,Summary,To understand:,various social,modelling,approaches,individual based models,dynamic MSM,how a typical dynamic MSM is structured,how a typical dynamic MSM works,importance of data for a MSM,alternative,modelling,approaches that may compliment MSM,Learning objectives,Social Systems are“messy,boundaries,large and,complex(Moss,2000),Approaches of modelling social systems,Individual Based Models(IBM):,MSM(,Microsimulation,Model),CA(Cellular Automata),ABM(Agent Based Model),Approaches of modelling social systems,MSM,Approaches of modelling social systems,+,t=1,2,t=n,MSM:,Static vs Dynamic,Approaches of modelling social systems,Type of MSM,characteristics,Ageing technique,Entity,Interactivity,Time,Population,Change,Impact of previous step on the next,Static,Deterministic/Stochastic,Static ageing,No,No time element/stocks of entities updates,No,No,Dynamic,Stochastic,Dynamic ageing,Possible,Change process and events built in,Yes,Yes,Advantages of Static MSM:,quicker to run,simpler to develop and understand,lower costs:computing resources,skills and development time,often with very detailed programme simulations,Approaches of modelling social systems,Advantages of Dynamic MSM:,more details,better representation of population ageing,especially in long term,as it accounts interim changes in economic and demographic trends,generally accepted more realistic representation of micro population unit changes,Approaches of modelling social systems,MSM:,Spatial and non-Spatial,Approaches of modelling social systems,“One can not be at two places at the same time.,(Hgerstrand,1967),“Means are to be employed somewhere.,(De Man,1998),People have to live in a local area and they are affected by local environment.,CA,source,:,ABM,An application of Leeds:modelling objectives,Modelling objectives:,To develop a complete,representation,of the Leeds population at a fine spatial scale,To produce rich,detailed and robust,forecasts,of the future population of Leeds,To investigate,scenarios,which relate demographics to service provision,Modelling Description,Dynamic representation of key demographic events/transactions in a geographically identified population,Macrosimulation,and,microsimulation,models(MSM)are alternative ways of realising the processes(van,Imhoff,and Post,1998),We use a spatial MSM of the population and its dynamics,but the structure parallels the macro multi-state cohort-component(MSCC)projection model,An MSM depends on good data on the important transitions experienced by individuals,We experimented with an Agent Based,Model(ABM,)for a sub-population,students,where empirical data on migration has often proved problematic,What does that mean?,Scale,Leeds population:760,000,Each individual has about 60 individual variables+,20 household variables+area variables,Various probabilities/rates,eg,:localised single year of age based mortality probabilities,Movement,interaction and behaviour,Distinctive behaviours from various population groups in different demographic processes,Interdependency of household and individual variables in different demographic processes,Demographic processes in the MSM,6 modularised processes:,simple processes,complex processes,individuals and households,Initial Results:Leeds population change,Initial Results:small area variation,Characteristics of student migrants,Students are highly mobile during their studies in the universities,Mostly only move around the area close to the universities where they study,NOT in the suburban areas,Most of them will leave the city once they finish their study,NOT growing old in the suburban areas,Due to the replenishment of the student population each year,the population of the small areas where university student stay tends,to remain,younger than other areas,ABM,An alternative approach that models individuals as agents through their interactions with each other and the environment that they live in.,It is very flexible to introduce heterogeneous agents with distinctive behaviours through their built-in rules,It is,useful in modelling features of the,population where,knowledge and data is lacking,(,Billari,et al.,2002).,ABM experiments:Student Migrants,We recognise the following groups:,First year undergraduates,Other undergraduates,Master students,Doctoral students,We apply the following general rules:,Each group is allowed set years to stay in the area,Students prefer to stay with their fellow students,Students stay close to their university of study,subject to housing availability,They dont“do marriage and fertility,Observed Predicted,Comparison of Results:Pure MSM,Comparison