“…Southern states do on average have higher obesity rates than other states (Centers for Disease Control and Prevention, 2009).Of course, some of this difference could be the causal effect of Walmart, while much of the remaining regional variation should be captured by the county fixed effects, controls for potential confounders such as income and education, and density à year interactions. Also, while Bentonville is technically in the south, its location in the northwest corner of Arkansas is less than 500 miles from the geographic center of the US Columbus, GA and Denver, CO are nearly equidistant from Bentonville, as are Shreveport, LA and Saint Louis, MO as well as Knoxville, TN and Madison, WI (Carden et al, 2009a). Nonetheless, the possibility for bias remains.…”