Methodology for modeling household time allocation behavior

It is well known that members of a household often interact in making decisions about different activities that they perform and the time that is involved. However, little research on such group decision-making issues has been conducted to date in transportation research. In the context of time allocation, the authors previously proposed two types of household time allocation models within a random utility maximization framework. The first one assumes a multi-linear type of household utility function, while the second one adopts an iso-elastic class of welfare function as the household utility function. fn representing household decision-making mechanisms, the two types of functions functionally overlap and theoretical comparisons suggest that the iso-elastic utility function seems more general and flexible. In this paper, these two models are estimated and empirically compared by using the same activity diary data collected in a depopulated region in Japan. The study confirms that both models have a relatively high and nearly equal goodness-of-fit. It also provides further evidence that 1) households interact in making decisions, 2) male household members do have most influence on the decision-making process and 3) the household time allocation model seems good at describing female's time allocation behavior. Moreover, similar household decision-making rules are observed in the sense that the household members first form their own separate utility function as a weighted average of part-worth utilities and then maximize the resulting function. However, in spite of nearly equal model accuracy and the similarity of household decision-making rules, the two models estimate a different relative influence of household members. This implies that household members might follow different paths during the negotiation process to arrive at their most preferred outcomes.