Chapter 8: A Model of Time Use and Expenditure of Pedestrians in City Centers

This paper deals with time use and expenditure of pedestrians in city centers. A new resource allocation model is developed to describe how pedestrians allocate their available time and expenditure budgets to various activities using a utility-maximizing framework. A pedestrian’s utility derived from his/her consumption behavior is defined using a multi-linear function, which is further composed of time-specific and expenditure-specific utilities and interactivity interactions. The interactivity interactions consist of three parts: time-to-time, expenditure-to-expenditure, and time-to-expenditure interactions. By maximizing the pedestrian’s utility, conditional on available time and expenditure budgets, time use and expenditure functions for all the activities are derived as a nonlinear simultaneous-equation model system. A function measuring pedestrian-specific value of activity time is also derived. Seemingly unrelated regression method is applied to estimate the model system. The limitation of this study is that spatial elements and activity participation are ignored. To estimate the model, weekend activity diary data were collected in the central area of Hiroshima City, Japan in November 2004. The validity of the model was empirically confirmed. Introducing interactivity interactions greatly improved model accuracy. It was found that existing models significantly underestimate the value of activity time. Many individual attributes were not sensitive to model structures. Employment status was an exceptional and in particular the proposed model revealed that its influence could account for more than 80% of the total utility. Influence of household income was extremely low.