Impact of Life-course events on hierarchical Vehicle transaction durations: Case of a Developing country.

Vehicle ownership is a multifaceted domain of study; this paper focuses on vehicle transactions, which encompasses the temporal aspect of vehicle ownership. Life-course events have found their way into vehicle ownership models for developed countries. Owing to the high cost and unavailability of panel data, the same cannot be said for developing countries. Contrary to developed countries, vehicles owned by people in developing countries vary considerably in many aspects. The most common visible difference is the mix of two-wheelers, their varieties, and four-wheelers. In light of a prevalent hierarchy of vehicle types, people are often involved in upgrading or downgrading their vehicles. Accounting for such transactions is critical to depicting vehicle ownership behaviour accurately. To the best of the authors' knowledge, no study has attempted to understand the movement of vehicle owners along the hierarchy of vehicles owned. This study demonstrates a workaround by constructing a longitudinal dataset using retrospective mobility biography interviews. We used 420 data points from 60 interviews, with an average length of 40 minutes, to fit a competing risk-hazard duration model and find out how different life events and household structure traits affect the length of different types of transactions. Marriage, relocation, childbirth, the start of employment, and retirement were found to be the life-course events that impacted either or multiple vehicle transaction durations. Household structure attributes like prior vehicle type(s) owned, total number of workers, and number of teenagers also impact vehicle transaction durations. Although this study validates the relationship between life-course events and vehicle transactions in a developing country, aspects like heterogeneity, macroeconomic attributes, and neighbourhood attributes can be addressed in future studies. An application-oriented extension of this could be a coupling with the vehicle type choice model, making it more utilitarian.