Demographic models Lecture 2 Stages and steps of

Demographic models Lecture 2. Stages and steps of modeling. Demographic groups, processes, structures, states. Processes: fertility, mortality, marriages, divorces, family formation, migrations, mutations, age structures, outcomes of pregnancy (duration, birth weight, foetus survival), change of household composition. Independent variables, phase variables, parameters of a model. Time, age, period, change of demographic status. Adjustment of a model, estimation of parameters, testing a model. Disclosure of limitations of a model. Testing of hypothesis. Initial data: complete incomplete, precise – approximate, aggregate – detailed. Homogeneous – heterogeneous population (homogeneity – heterogeneity of population). Heuristics, scenario.

Demographic models Stages and steps of modeling Demographic structure – distribution of population by the attributes connected with population reproduction. Age structure Sex structure Marital structure Family structure Territorial distribution (settlement) Ethnic structure Occupational structure

Demographic models Example: Stages and steps of Age-sex modeling structure

Demographic models Stages and steps of modeling group – a set of persons, families, Socio-demographic households by the list of attributes identical within one group. Attributes: Age Sex Marital status Family type Household size Ethnicity Educational attainment Region of residence Type of settlement A person (a family) is and moves in the state space. Part of attributes of a person is not within a human control.

Demographic models Stages and steps of modeling Demographic processes (social, ecological) Birth Death Conclusion of marriage Moving to a new place of residence Border crossing Gene mutation Pregnancy outcome (birth weight, duration, foetus survival) Leaving parental home Divorce Environmental pollution (for example СО) Change of settlement type and region

Demographic models Stages and steps of modeling Example: ecological model (opening of EPC-2010, 1 September, 2010)

Demographic models Stages and steps of modeling Example: ecological model (opening of EPC-2010, 1 September, 2010)

Demographic models Stages and steps of modeling Independent variables Time Age Duration of residence Years of schooling Marriage duration Year of birth

Demographic models Stages and steps of modeling Phase variables – portray population structures and volume of demographic processes taking place Size of socio-demographic group Number of births Population size in a region Number of migrants Population density Flow of immigrants per year

Demographic models Stages and steps of modeling Model parameters – describe speed and other characteristics of demographic processes under consideration Force of mortality Age-specific fertility rate Life span Migration mobility Number of regions

Demographic models Stages and steps of modeling Adjustment of model. Estimation of model parameters Initial status – state of population in the initial time Boundary conditions – define the values of model variables at age=0, arrived to the region depending on another variables Equations of model – balance relationships formalizing conservation equations for population structures and processes in a given model Estimation of model parameters on the ground of available population statistics (may require interpolation, extrapolation, utilizing of model life tables and other demographic tables)

Demographic models Stages and steps of modeling Study of the model (1) Testing – defining the extent of precision, correctness, validity of the model equations Detecting the limitations of the model Testing of hypothesizes (independence of events, form of parameters distribution, number of demographic groups, dependence on factors, …) Scenario – assembly of parameter values on the horizon period of model validity on the assumptions of not only

Demographic models Stages and steps of modeling Study of the model (2) Study of limit properties of model variables for different scenarios Recognition of indirect dependency of demographic variables upon variation of model parameters Aggregation of internal, micro, structural variables, calculation of macro, crude, general indicators Population projection

Demographic models Stages and steps of modeling Discrepancies and limitations of modeling Initial data: complete - incomplete, precise – approximate, aggregate – detailed. Homogeneity – heterogeneity of population (homogeneous – heterogeneous population) Unobserved (hidden) heterogeneity Balancing of two-sex marriage models Compatibility of indicators for demographically different subpopulations and the whole population