As Walmart grew rapidly into the world's largest corporation, many critics worried about the effect of its stores on local communities, particularly small towns with many "mom and pop" stores. There have been several studies on the economic impact of Walmart on small towns and local businesses, jobs, and taxpayers. In one, Kenneth Stone, a Professor of Economics at Iowa State University, found that some small towns can lose almost half of their retail trade within ten years of a Wal-Mart store opening.[21] However, in another study, he compared the changes to what small town shops had faced in the past — including the development of the railroads, the advent of the Sears Roebuck catalog, as well as the arrival of shopping malls — and concluded that shop owners who adapt to changes in the retail market can thrive after Wal-Mart arrives.[21] A later study in collaboration with Mississippi State University showed that there are "both positive and negative impacts on existing stores in the area where the new supercenter locates."[22]

In the aftermath of Hurricane Katrina in September 2005, Walmart was able to use its logistical efficiency in organizing a rapid response to the disaster, donating $20 million in cash, 1,500 truckloads of free merchandise, food for 100,000 meals, as well as the promise of a job for every one of its displaced workers.[23] An independent study by Steven Horwitz of St. Lawrence University found that Walmart, The Home Depot and Lowe's made use of their local knowledge about supply chains, infrastructure, decision makers and other resources to provide emergency supplies and reopen stores well before FEMA began its response.[24] While the company was overall lauded for its quick response – amidst the criticisms of the Federal Emergency Management Agency – several critics were nonetheless quick to point out that there still remain issues with