A Trip to Sam’s Club and Wal-Mart

Charles Courtemanche and I have gotten a little bit of coverage with our paper on Big Box retailers and obesity.  Here’s the abstract:

We estimate the impacts of Wal-Mart and warehouse club retailers on height-adjusted body weight and overweight and obesity status, finding robust evidence that non-grocery selling Wal-Marts reduce weight while grocery-selling Wal-Marts and warehouse clubs either reduce weight or have no effect. The effects appear strongest for women, minorities, urban residents, and the poor. We then examine the effects of these retailers on exercise, food and alcohol consumption, smoking, and eating out at restaurants in order to explain the results for weight. Most notably, the evidence suggests that all three types of stores increase consumption of fruits and vegetables while reducing consumption of foods high in fat. This is consistent with the thesis that Wal-Mart increases real incomes through its policy of “Every Day Low Prices,” making healthy food more affordable, as opposed to the thesis that cheap food prices make us eat more.

We certainly welcome constructive criticism, and we will present it at the University of Arkansas and at West Virginia University before submitting it for publication.  For what it’s worth, contra the blog comments suggesting that we obviously don’t shop at Wal-Mart and Sam’s Club, my wife and I just went there today.  Among our purchases: soy milk, organic flaxseed cereal, grape tomatoes, OJ, and compact fluorescent light bulbs.  At the margin, I suspect that this stuff is cheaper than it would be otherwise because of Wal-Mart’s innovations in logistics and distribution.  We haven’t looked at the relationship between Wal-Mart and prices of these goods directly, but Emek Basker has looked at Wal-Mart’s effect on prices in some categories.