allowed to return to work. Tires with the highest rates of failure were manufactured in the months right before the union went on strike but after labor negotiations had begun, and later after union workers began to cross the picket line and work without a contract alongside replacement workers. Other Firestone factories (Joliette, Quebec and Wilson, North Carolina) also produced the same tire models but had far lower failure rates. Failure rates at the Decatur plant before the labor negotiations began, while the replacement workers worked without union workers, and after the labor negotiations ended, were comparable to the failure rate of tires manufactured at the Joliette and Wilson plants. Other studies have found that labor unrest reduces the quality of work by union members, suggesting that there should be additional inspections and heightened scrutiny by regulators during strikes. Recall On August 17, 1999, Ford in Saudi Arabia began replacing Firestone tires on unsold Ford Explorers and to offer steep discounts on replacement tires to customers who returned to Ford dealers for regular maintenance. While this was not officially a recall Ford still replaced Firestone tires on 6,800 Ford Explorers and Mercury Mountaineers. In February 2000, Ford began to recall Firestone tires in Malaysia and Thailand. In May 2000, Ford recalled 150,000 Firestone tires on Explorers in Venezuela, Colombia and Ecuador. In August 2000 Bridgestone/Firestone issued a recall in Venezuela of 62,000 Venezuelan made Firestone tires. The recall was estimated to cost $6 million. On August 9, 2000, Firestone issued a recall covering 6.5 million P235/75 R15 Firestone ATX and ATX II tires and P235/75R15 Wilderness AT tires manufactured after 1991 and 1996 respectively. The recall covered all ATX and ATX II tires regardless of which plant they originated from but only covered Wilderness AT tires from Firestone's Decatur plant. Firestone had produced 14.4 million tires that were covered by this recall but it was estimated that only 6.5 million remained in service. Wilderness AT tires manufactured in Joliette, Quebec and Wilson, North Carolina were not included in the recall. On August 21, 2000, Ford halted production at three truck assembly plants so that 70,000 tires could be diverted towards the recall effort. P235/75 R15 tires became scarce and Ford authorized dealers to install replacement tires from companies other than Firestone. Both Ford and Firestone looked for replacement tires internationally. On May 22, 2001, Ford announced a voluntary recall of