No Time to Lose? Time Constraints and Physical Activity

Although individuals are all endowed with the same time budgets, time use patterns differ owing to heterogeneity in preferences and constraints. In today's health policy arena there is considerable discussion about how to improve health outcomes by increasing levels of physical activity. In this paper, we explore how individuals endowed with different levels of human capital allocate time to physically-demanding activities that we characterize as health-producing behaviors. Our data are drawn from multiple years of the American Time Use Survey (ATUS), which are based on daily time use diaries and include information on detailed physical activity time uses. Since ATUS time use categories are mutually exclusive and exhaustive -- i.e. "multitasking" is not accommodated -- we employ a novel econometric share equation techniques to enforce the adding-up requirement that time use is constrained to 1,440 minutes per day. We find that differential human capital endowments result in different manifestations of how time is used to produce health. While more-educated individuals, e.g., sleep much less than less-educated individuals, they utilize some of the time so liberated to exercise and work more. We find as well that various features of individuals' environments, broadly defined, play important roles in time allocation decisions.