Wal-Mart’s impact on wages and benefits was most clearly shown in 2002 when it announced plans to open 40 Supercenters in California over the next three years. California was then a stronghold for Safeway, Albertsons, and Kroger, three of the largest grocery chains in the country. In contrast to Wal-Mart, which has succeeded in keeping unions out of its U.S. stores, these three chains have unionized workforces, and their workers were paid about 50 percent more than workers at Wal-Mart and had much better health insurance programs. The big three chains believed, with some justification, that these costs would be a fatal handicap in the coming battle to defend their market share against Wal-Mart. They therefore demanded that their workers accept a new contract that contained no wage increases and would require workers to contribute substantially to their health insurance. In effect, the workers were being asked to take a pay cut. The result was the biggest strike in California’s history, but against their employers’ fear of Wal-Mart, even 70,000 united workers could gain little. After 20 weeks on strike, they agreed to take a contract with reduced benefits. Wal-Mart, or the threat of it, was forcing wages and benefits down.