>I'm being vague, but I think my concern is that the focus on "monopolistic behavior" is archaic. I take your point. However, at least in the United States[0]

>I'm being vague, but I think my concern is that the focus on "monopolistic behavior" is archaic. I take your point. However, at least in the United States[0], the law does not require an entity to be a monopoly to engage in behavior that is anticompetitive and/or violates anti-trust laws. In fact, the topic at hand (Visa's proposed acquisition of Plaid) doesn't have a "monopoly" component at all. Rather, IIUC the DOJ is arguing that it runs afoul of section 7 of the Clayton Antitrust Act[1] which addresses mergers and acquisitions that limit competition. I don't disagree with your assessment of the situation, but I do think that existing law (and jurisprudence expanding on that law) address the vast majority of the issues impact competition today. [0] https://en.wikipedia.org/wiki/United_States_antitrust_law https://en.wikipedia.org/wiki/United_States_antitrust_law [1] https://en.wikipedia.org/wiki/Clayton_Act_of_1914#Section_7 https://en.wikipedia.org/wiki/Clayton_Act_of_1914#Section_7