Monopolistic competition Advertizing 1 Competition 1 Competitive markets 1 Condition 1 Finite number 1 Informative advertising 1 Informative advertizing 1 International trade 1 Marketing 1 Product differentiation 1 Service sector 1 Standard assumptions 1 Trade costs 1 United States 1 Welfare 1 Welfare effects 1 competition (economics) 1 international trade 1 labor productivity 1 manufacturing 1 monopoly 1 service sector 1 trade flow 1 trade liberalization 1 wage 1