George F. Will, writing in the Washington Post, gives the difference Wal-Mart makes:
The median household income of Wal-Mart shoppers is under $40,000. Wal-Mart, the most prodigious job-creator in the history of the private sector in this galaxy, has almost as many employees (1.3 million) as the U.S. military has uniformed personnel. A McKinsey company study concluded that Wal-Mart accounted for 13 percent of the nation’s productivity gains in the second half of the 1990s, which probably made Wal-Mart about as important as the Federal Reserve in holding down inflation. By lowering consumer prices, Wal-Mart costs about 50 retail jobs among competitors for every 100 jobs Wal-Mart creates . Wal-Mart and its effects save shoppers more than $200 billion a year, dwarfing such government programs as food stamps ($28.6 billion) and the earned-income tax credit ($34.6 billion).
People who buy their groceries from Wal-Mart — it has one-fifth of the nation’s grocery business — save at least 17 percent. But because unions are strong in many grocery stores trying to compete with Wal-Mart, unions are yanking on the Democratic Party’s leash, demanding laws to force Wal-Mart to pay wages and benefits higher than those that already are high enough to attract 77 times as many applicants than there were jobs at this store.
The full article can be found here.