The Anti-Commons Revisited

Intellectual property scholars and policymakers often assert that technology and creative markets suffer from “anti-commons” (“AC”) effects that restrain innovation within a web of conflicting intellectual property claims. A minority view asserts that market players have incentives and capacities to correct for AC effects through transactional solutions. To assess the relative merits of each side of this debate, I review a large and diverse body of empirical evidence relating to AC effects in contemporary and historical markets. I independently replicate the most controversial empirical findings, supplement additional research on selected markets, and provide a survey of all documented IP-pooling arrangements in U.S. markets since 1900. The weight of the evidence strongly favors the minority view. Evidence for AC effects is scarce while evidence that markets correct for AC effects is abundant. AC effects are typically preempted or mitigated through cooperative arrangements among small numbers of IP holders or transactional solutions devised by entrepreneurial intermediaries for large numbers of IP holders. This pattern recurs over a diverse array of markets and periods, including automobiles, petroleum refining, aircraft, and radio communications in the early to mid-20th century, and information and communications technology markets from the late 20th century through the present. Contrary to standard assumptions, there is little evidence that these markets experienced reduced or delayed innovation or output despite intensive levels of patent issuance and litigation