If we are to gain an accurate perspective on the impact of antitrust laws and policies on the behavior of firms in the real world, we must adopt a micro-microeconomic approach which focuses not on how rational, profit-maximizing firms will theoretically behave, but upon how late twentieth-century American managers and executives actually behave. This article attempts to begin that task.

Part I of this article examines the justifications for focusing on individual managers rather than profit-maximizing firms as the key actors in antitrust law. Part II looks at contemporary management mores and practices and develops some generalized "rules of the game" for how managers advance their careers in present-day American firms. Finally, Part III applies the rules to predict how managers might well guide their firms in three scenarios vital to modern antitrust law: entry into new markets, exclusion of competitors, and collusion among competitors.