The document provides an introduction to airline industry economics. It discusses how air travel has grown globally and facilitated other industries. It describes the airline industry structure as an oligopoly with few dominant firms and high barriers to entry. It outlines the oligopolistic characteristics airlines exhibit and discusses factors like market share, mergers, mutual dependence, and non-price competition. The document also covers the airlines' economic characteristics such as high costs of labor, fuel, and technology changes. It analyzes how airlines are sensitive to economic fluctuations.