Working Times and Overweight: Tight Schedules, Weaker Fitness?

We study the causal effect of a change in working times on overweight and obesity drawing from evidence from a national policy (the Aubry reform) implemented in the beginning of the past decade in France that reduced the work week from 39 to 35 hours, or 184 hours per year. We draw on two sources of identification. First, one region, Alsace-Mosselle, blunted its impact by counting two existing public holidays towards the 184-hour reduction. In this region, hours of work per year only fell by 168 until 2003, when it was forced to fully comply with national policy. Second, we use longitudinal data from GAZEL (INSERM) 1997-2006 that contains detailed information about health indicators, including measures of height and weight for employees of EDF-GDF which was among the very first to implement the 35-hour workweek in 2000. Drawing from a difference-in-differences strategy, we estimate the effect of a differential reduction in working times on body weight. Our results show evidence of 6.7 percentage points increase in the probability of overweight among blue collar workers, when the exposure to the reform. In contrast, we find no effect among white-collar workers. The effect is driven by an increase in overweight among normal weight individual and a reduction of obese blue-collar employees by 2.6pp. The effects are robust to different specifications and placebo tests.