Activity and transportation decisions within households

Households are often responsible for labour supply, time allocation, transportation and many other decisions. Yet, research in both economics and transportation was traditionally dominated by so-called unitary models that treat households as single decision-making units with a representative individual. This began to change with the development, in the field of Economics of the Family, of non-unitary models that recognize differences in household members’ preferences, and attempt to describe the joint decision-making processes within households. Application of non-unitary models took off in the transportation literature with the special issues on modelling intra-household interactions edited by Bhat and Pendyala, 2005 [24] and Timmermans and Zhang, 2009 [115]. This chapter reviews the development of integrated models of household activity and transportation from the perspective of the Economics of the Family. These models have been applied to long-run decisions such as residential and workplace location and vehicle ownership, as well as short-run decisions including activity schedules, transport mode, and departure time. Non-unitary models go well beyond conventional discrete choice models by accounting for individual family members’ preferences, and within-family decision-making processes. The models feature new concepts specific to within-family interactions, including repeated interaction, bargaining, altruism, and Pareto optimality.