Although the supplier power of Boeing and Airbus is strong, three factors moderate their bargaining positions somewhat. First, the suppliers of commercial airliners depend heavily on commercial airlines for their revenues. Second, Boeing and Airbus are unlikely to threaten forward integration and become commercial airlines themselves. Finally, industry structures are not static, but can change over time. In the last few years, several of the remaining large domestic U.S. airlines have merged (Delta and Northwest, United and Continental, and American and U.S. Airways), which changed the industry structure in their favor. There are now fewer but even larger airlines remaining. This fact increases their buyer power, which we turn to next.