Representing household time allocation behavior by endogenously incorporating diverse intra-household interactions: A case study in the context of elderly couples

Travel behavior models assuming individual decision-making processes have been a dominant theme in transportation studies. While the assumption that an individual can decide on all relevant aspects of some types of travel behavior may be reasonable, in many other aspects household members interact before making decisions about different activities that they perform and the time that is involved. On the other hand, different types of households may show different group decision-making mechanisms. In other words, there might exist diverse intra-household interactions during joint decision-making processes. To reflect this point, this paper aims to develop a new household time allocation model based on the iso-elastic class of social welfare function, which can include different types of household utility functions as special cases (e.g., Nash, utilitarianism, autocratic and max–min types). Throughout this empirical analysis, which uses an activity diary data collected in a depopulated region of Japan, the effectiveness of the proposed model is confirmed. Furthermore, the model’s applicability in evaluating transportation policies for elderly people is examined based on a simulation analysis.