The United States Government and its Federal Aviation Administration (FAA) are particularly influential in this regard since they oversee the largest air transport market in the world. Regulations by the United States and European governments may prove to be a major driving force for orders for new aircraft and engines in the years to come. Similarly, the deregulation of European airlines, already begun in the early 1990s, holds the promise of expanded market prospects for smaller regional jets. Trade in larger commercial jetliners has been virtually tariff-free since 1979 under the General Agreement on Tariffs and Trade (GATT).