Body mass and wages: New evidence from quantile estimation

- Impact of body mass index (BMI) on wages differs across the wage distribution.
- BMI-related wage penalty is increasing in wages for whites and Hispanics.
- High income earners have differential incentives to maintain a low body weight.
- Substantial differences between unconditional and conditional quantile estimates.

I estimate the effect of body mass index (BMI) on wages across the unconditional distribution of wages. I find that for whites and Hispanics the effect of BMI is generally decreasing across the wage distribution; at the .9 quantile of the wage distribution, a two standard deviation increase in BMI reduces wages by 8% for white males, 13% for white females, 9% for Hispanic males, and 16% for Hispanic females. Conversely, at the .1 quantile, a two standard deviation increase in BMI affects wages by less than 2% for all these groups. For black males, the effect of BMI is positive, and either increasing or non-linear in wages. For black females, the estimates tend to be more uniform across the wage distribution. I discuss possible explanations for these inter-quantile differences including preference discrimination, productivity differences, and statistical discrimination. The results point to a new explanation for the observed correlation between socioeconomic status and body weight: individuals with higher income earning potential have differential incentives to maintain a lower BMI.