Growing consumption of increasingly less expensive food, and especially fast food, has been cited as a potential cause of increasing rate of obesity in the United States over the past several decades. Because the real minimum wage in the United States has declined by as much as half over 1968-2007 and because minimum wage labor is a major contributor to the cost of food away from home, the authors hypothesized that changes in the minimum wage would be associated with changes in bodyweight over this period.
To examine this, they use data from the Behavioral Risk Factor Surveillance System from 1984-2006 to test whether variation in the real minimum wage was associated with changes in body mass index (BMI). They also examine whether this association varied by gender, education and income, and used quantile regression to test whether the association varied over the BMI distribution. The authors also estimate the fraction of the increase in BMI since 1970 attributable to minimum wage declines. They found that a $1 decrease in the real minimum wage was associated with a 0.06 increase in BMI. This relationship was significant across gender and income groups and largest among the highest percentiles of the BMI distribution. Real minimum wage decreases can explain 10 percent of the change in BMI since 1970.
The study concluded that declining real minimum wage rates have contributed to the increasing rate of overweight and obesity in the United States. Studies to clarify the mechanism by which minimum wages may affect obesity might help determine appropriate policy responses.