The document discusses the duopoly between Boeing and Airbus in the commercial aircraft manufacturing industry. It begins by defining a duopoly as a market controlled by two companies. It then provides characteristics of a duopoly such as two firms controlling the majority of market share and price competition depending on quantity supplied by each firm. The document analyzes the commercial aircraft industry specifically, noting how mergers have consolidated it into just Boeing and Airbus. It discusses aspects of their competition like diversified product portfolios, regulations around safety, and how prices and strategies are determined. Finally, it reinforces that a duopoly has two producers dominating one market, which is the current situation between Boeing and Airbus.