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.- 2.1.1 Bilaterals and Traffic Rights.- 2.1.2 Capacity Controls.- 2.1.3 Price Coordination.- 2.2 Deregulation and Liberalization.- 2.2.1 The U.S. Experience.- 2.2.2 Renegotiating Bilaterals.- 2.2.3 Towards European Liberalization.- 2.3 Economies in Aviation.- 2.3.1 Distinguishing Scope from Scale.- 2.3.2 Looking for Economies of Scale.- 2.3.3 The Economies of Scope Hypothesis.- 2.4 Summary.- 3 Characteristics of Services.- 3.1 General Characteristics.- 3.1.1 Historical Views.- 3.1.2 Defining Services.- 3.1.3 Characteristics of Trade in Services.- 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.- 4.2.1 Problems with the Standard Paradigm.- 4.2.2 A Selective Review.- 4.2.3 Analysis.- 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.- 5.2.1 Comparative Costs.- 5.2.2 The Heckscher-Ohlin Framework.- 5.2.3 Contestability.- 5.2.4 Oligopoly.- 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.- 6.1.1 Case 1.- 6.1.2 Case 2.- 6.1.3 Case 3.- 6.1.4 Summary.- 6.2 Trade in aviation services.- 6.2.1 The direction of trade.- 6.2.2 The extent of exports.- 6.2.3 Trade implications of protectionism.- 6.2.4 Trade implications of deregulation.- 6.3 Summary.- 7 Empirical Research.- 7.1 Explaining Exports.- 7.2 Explaining Passengers Carried.- 7.2.1 The Working Hypothesis.- 7.2.2 Direct Tests for Economies of Scope.- 7.2.3 Interpreting the Working Hypothesis.- 7.2.4 Data Gathering.- 7.2.5 Testing the Working Hypothesis.- 7.3 Summary and Conclusions.- 8 Policy Conclusions.- 8.1 Aviation Policy.- 8.1.1 Limits to Scope.- 8.1.2 Deregulation.- 8.1.3 Subsidization.- 8.2 Trade Policy.- 8.2.1 Aviation Trade Policy.- 8.2.2 Development Policies.- 8.2.3 The Uruguay Round GNS.- 8.2.4 Beyond the Uruguay Round.- 8.2.5 Trade in Services.