The Demographic Transition Model accounts for changes in the distribution of households by type over time, using an algorithm analogous to that used in the Economic Transition Model. In reality, these changes result from a complex set of social and demographic changes that include aging, household formation, divorce and household dissolution, mortality, birth of children, migration into and from the region, changes in household size, and changes in income, among others. The data (and theory) required to represent all of these components and their interactions adequately are complex, and this set of behaviors remain to be implemented in UrbanSim. Instead, the Demographic Transition Model, like the Economic Transition Model described above, uses external control totals of population and households by type (the latter only if available) to provide a mechanism for the user to approximate the net results of these changes. Analysis by the user of local demographic trends may inform the construction of control totals with distributions of household size, age of head, and income. If only total population is provided in the control totals, the model assumes that the distribution of households by type remains static.
As in the economic transition case, household births are added to a list of movers that will be located by the Household Location Choice Model. Household deaths, on the other hand, are accounted for by this model by removing those households from the housing stock, and by properly accounting for the vacancies created by their departure. The demographic transition model is analogous in form to the employment transition model described above.