ECON 431 is a course in industrial organization, the study of firms in markets. This field analyzes the acquisition and use of market power by firms, strategic interactions among firms, and the role of government competition policy. We will approach this subject from both theoretical and applied perspectives, emphasizing the use of game theory and important antitrust cases such as US v. Microsoft. Course assignments will include occasional problem sets, a midterm and final, as well as a multi-week competitive strategy game: teams of students will compete across a number of simulated markets, making decisions about pricing, manufacturing capacity, and entry / exit.