IHR Health Economics Group Seminar

Increasing the level of physical activity in the population remains a major policy concern. In order to devise effective interventions it is crucial to know what determines whether people engage in physical activity. Several potential determinants have been explored including socio-economic characteristics, time constraints and motivation.

In the Grossman model, physical activity is considered to be a health investment which has short term costs (time and financial costs of engaging in physical activity) and long term benefits (improved health). Given the differential timing of costs and benefits, it can be hypothesised that individuals with high time preference rates are less likely to invest.

The main interest in this paper is in the role of time inconsistent preferences. Individuals often plan to engage in physical activity next week but fail to follow through when next week arrives. This can be explained by the enhanced significance that individuals attach to outcomes that occur now (present bias). This paper examines the relationship between time preference, present bias and physical activity participation. The paper uses the 2006 National Longitudinal Survey of Youth (NLSY) data which has a rich set of variables including time preferences elicited using stated preference methods and a relatively large sample of over 6000 individuals for analysis.

Preliminary results show that i) time preferences significantly impact women’s physical activity participation but not men’s, and ii) that present bias influences physical activity participation decisions in women but not in men. The results suggest that pre-commitment strategies may be effective in encouraging physical activity participation in women.

For further information please contact l.k.watson@exeter.ac.uk