The economic impact felt by local businesses when a large firm such as Wal-Mart opens a location in the area. The Wal-Mart effect usually manifests itself by forcing smaller retail firms out of business and reducing wages for competitors' employees. Many local businesses oppose the introduction of Wal-Marts into their territories for this reason.

The Wal-Mart effect is not all bad; it can also curb inflation and help to keep employee productivity at an optimum level. The chain of stores can save consumers billions of dollars, but may also reduce wages and competition in an area.