Evaluation-based coordination schemes for frontier AI face antitrust obstacles because collective pausing agreements among competing developers could be construed as cartel behavior

GovAI's Coordinated Pausing proposal identifies antitrust law as a 'practical and legal obstacle' to implementing evaluation-based coordination schemes. The core problem: when a handful of frontier AI developers collectively agree to pause development based on shared evaluation criteria, this coordination among competitors could violate competition law in multiple jurisdictions, particularly US antitrust law which treats agreements among competitors to halt production as potential cartel behavior. This is not a theoretical concern but a structural barrier—the very market concentration that makes coordination tractable (few frontier labs) is what makes it legally suspect. The paper proposes four escalating versions of coordinated pausing, and notably only Version 4 (legal mandate) avoids the antitrust problem by making government the coordinator rather than the industry. This explains why voluntary coordination (Versions 1-3) has not been adopted despite being logically compelling: the legal architecture punishes exactly the coordination behavior that safety requires. The antitrust obstacle is particularly acute because AI development is dominated by large companies with significant market power, making any coordination agreement subject to heightened scrutiny.