Demand for housing

The main determinants of the demand for housing are demographic. However other factors like income, price of housing, cost and availability of credit, consumer preferences, investor preferences, price of substitutes and price of compliments all play a role.

The core demographic variables are population size and population growth: the more people in the economy, the greater the demand for housing. But this is an oversimplification. It is necessary to consider family size, the age composition of the family, the number of first and second children, net migration (immigration minus emigration), non-family household formation, the number of double family households, death rates, divorce rates, and marriages. In housing economics, the elemental unit of analysis is not the individual as it is in standard partial equilibrium models. Rather, it is households that demand housing services: typically one household per house. The size and demographic composition of households is variable and not entirely exogenous. It is endogenous to the housing market in the sense that as the price of housing services increase, household size will tend also to increase.

Income is also an important determinant. Empirical measures of the income elasticity of demand in North America range from 0.5 to 0.9 (De Leeuw, F. 1971). If permanent income elasticity is measured, the results are a little higher (Kain and Quigley 1975) because transitory income varies from year-to-year and across individuals so positive transitory income will tend to cancel out negative transitory income. Many housing economists use permanent income rather than annual income because of the high cost of purchasing real estate. For many people, real estate will be the most costly item they will ever buy.

The price of housing is also an important factor. The price elasticity of the demand for housing services in North America is estimated as negative 0.7 by Polinsky and Ellwood (1979), and as negative 0.9 by Maisel, Burnham, and Austin (1971).

An individual household’s housing demand can be modeled with standard utility/choice theory. A utility function, such as U=U(X1,X2,X3,X4,...Xn), can be constructed in which the households utility is a function of various goods and services (Xs). This will be subject to a budget constraint such as P1X1+P2X2+...PnXn=Y, where Y is the households available income and the Ps are the prices for the various goods and services. The equality indicates that the money spent on all the goods and services must be equal to the available income. Because this is unrealistic, the model must be adjusted to allow for borrowing and/or saving. A measure of wealth, lifetime income, or permanent income is required. The model must also be adjusted to account for the heterogeneousness of real estate. This can be done by deconstructing the utility function. If housing services (X4) is separated into the components that comprise it (Z1,Z2,Z3,Z4,...Zn), then the utility function can be rewritten as U=U(X1,X2,X3,(Z1,Z2,Z3,Z4,...Zn)...Xn) By varying the price of housing services (X4) and solving for points of optimal utility, that household's demand schedule for housing services can be constructed. Market demand is calculated by summing all individual household demands.