NBER -- Body Composition and Wages

URL: http://d.repec.org/n?u=RePEc:nbr:nberwo:13595&r=hea
This paper examines the effect of body composition on wages. They develop measures of body composition “ body fat (BF) and fat-free mass (FFM) “ using data on bioelectrical impedance analysis (BIA) that are available in the National Health and Nutrition Examination Survey III and estimate wage models for respondents in the National Longitudinal Survey of Youth 1979. Their results indicate that increased body fat is unambiguously associated with decreased wages for both males and females. This result is in contrast to the mixed and sometimes inconsistent results from the previous research using body mass index (BMI). They also find new evidence indicating that a higher level of fat-free body mass is consistently associated with increased hourly wages. Finally they present further evidence that these results are not the artifacts of unobserved heterogeneity and show their findings robust to numerous specification checks and to a large number of alternative BIA prediction equations from which the body composition measures are derived. This work addresses an important limitation of the current literature on the economics of obesity. Previous research relied on body weight or BMI for measuring obesity despite the growing agreement in the medical literature that they represent misleading measures of obesity because of their inability to distinguish between body fat and fat-free body mass. Body composition measures used in this paper represent significant improvements over the previously used measures because they allow for the effects of fat and fat free components of body composition to be separately identified. The work also contributes to the growing literature on the role of non-cognitive characteristics on wage determination.