Interdependences between household residential and car ownership behavior: a life history analysis

Once a transportation system is built or a land-use policy is carried out, it influences people's travel behavior and their lives for a long time period. It is therefore important for policy makers to understand people's decisions on travel behavior and lives over a longer time period. However, little has been known about the interdependences between life domains, especially over the life course (i.e., biographical interdependences) in the context of residential and car ownership behavior. To fill this gap, this study aims to clarify households' biographical interdependences relating to residential and car ownership biographies by explicitly incorporating the influence of household structure and employment/education biographies. Biography is defined based on a general concept of mobility that indicates a change occurring in a life domain. For this purpose, a Web-based life history survey was conducted in November 2010 and 1000 households living in major Japanese cities provided valid data. Aggregate analysis and exhaustive CHAID analysis were carried out, focusing on the occurrence times of mobilities in each biography. Results confirm obvious two-way cause-effect relationships over the life course between residential and car ownership biographies that are further influenced by household structure and employment/education biographies. Especially, not only short-term but also long-term state dependence and future expectations within and across life domains are clarified. Household structure and employment/education biographies are found to be more influential on residential biography than car ownership biography. Though residential biography is seen to be more influential on car ownership biography, the other two biographies also play an important role in explaining the car ownership mobility decision. All these findings suggest the necessity of developing intra-domain and inter-domain biographical interdependence models with flexible structures that capture the influences of state dependence and future expectations over different time scales in the life course in a unified framework.