Cost of Exclusion as a Proxy for Dominance in Digital Platform Regulation

While many regulations promoting consumer protection and competition apply throughout a sector, some economic regulations apply to “dominant” firms or firms with “market power.” Behavior that is harmless, or potentially even positive when done by smaller companies or in a more competitive marketplace, can be anticompetitive or harmful to consumers when done by dominant firms -- regardless of the firm’s actual intent. Defining what constitutes “dominant” (or even identifying a single market in which to make such a determination), presents many challenges using the traditional tools of analysis favored by antitrust enforcers and regulators. I therefore propose that we use the cost of exclusion (“COE,” because nothing in policy is taken seriously unless it has its own acronym) as the means of determining when we need to apply regulation to “dominant” firms. That is to say, the greater the cost to individuals and firms (whether as consumers or producers or any of the other roles they may play simultaneously on digital platforms), the greater the need for regulations to protect platform users from harm. If a firm is “too big to lose access to,” then we should treat that firm as dominant.