The paper investigates cartels, or agreements between competing firms that seek to influence prices for certain goods and services by controlling production and marketing. The author examines the neoclassical approach to cartels and proposes two additional approaches, behavioral and ethical, to expand existing research on cartels.Most mainstream studies tend to approach cartels from a neoclassical perspective, according to the author. This research approach gave rise to the so-called optimal deterrence theory, which has become the basis for antitrust policy in highly developed countries, Karbowski notes. The optimal deterrence theory is a point of reference for Karbowski in his article. He compares the optimal deterrence theory with the results of behavioral analyses and ethical reasoning focusing on cartels. According to the author, a behavioral approach makes it possible to show how the behavior of firms deviates from the path delineated by the standard optimal deterrence theory, based on assumptions of full rationality, perfect egoism and complete self-control of decision makers. These behavioral deviations can be explained by either internal (trait-based) or external (environmental) factors, Karbowski says. Ethical analysis makes it possible to expand the neoclassical approach to cartels by showing that cartel behavior can be viewed not only in pure economic terms, but also in terms of theft, deception and cheating, the author argues.