1 Aviation, Scope Economies and Services Trade.- 1.1 Liberalization Promotes Scope Economies.- 1.2 A Typical Traded Service.- 1.3 Trade in Services.- 1.4 Trade Policy Relevance.- 1.5 Structure.- 2 Aviation Facts.- 2.1 Regulated Markets.- 2.2 Deregulation and Liberalization.- 2.3 Economies in Aviation.- 2.4 Summary.- 3 Characteristics of Services.- 3.1 General Characteristics.- 3.2 Aviation Charateristics: a typical service.- 3.3 Why International Aviation Services?.- 4 Trade in Services.- 4.1 A Fresh Look.- 4.2 The Theory of Trade in Services.- 4.3 Empiricism in Trade in Services.- 4.4 Barriers to Trade in Services.- 4.5 Service and Development.- 4.6 Some GNS Issues.- 5 Trade in Aviation Services.- 5.1 Concepts.- 5.2 Theory and Empiricism.- 5.3 Comparative Advantage in Aviation.- 5.4 Aviation Services and Development.- 5.5 Aviation and Some GNS Issues.- 6 Modeling Aviation Services Trade.- 6.1 Determining output.- 6.2 Trade in aviation services.- 6.3 Summary.- 7 Empirical Research.- 7.1 Explaining Exports.- 7.2 Explaining Passengers Carried.- 7.3 Summary and Conclusions.- 8 Policy Conclusions.- 8.1 Aviation Policy.- 8.2 Trade Policy.