Hub-and-Spoke Cartels Revisited: Incentives, Proof, and Algorithmic Intermediation

Hub-and-spoke cartels occupy an uneasy position in antitrust enforcement. Although structurally hybrid, combining vertical relationships with horizontal coordination, they generate competitive harm traditionally associated with cartels while raising distinctive evidentiary and analytical challenges. This paper revisits hub-and-spoke cartels through an integrated economic and legal perspective. It argues that their persistence cannot be explained by facilitation of coordination alone, but require