Replication Data for: Convergent Flexibility: How International Law Keeps Pace with Technological Change

If change is the only constant, how does the law keep pace with technology? Without a centralized judiciary, international law should be especially susceptible, yet it can be remarkably adaptable in practice. I argue that efforts to minimize legal ambiguity, long seen as integral to compliance, can hinder its application to new technologies. Drawing on first principles from psycholinguistics, the theory differentiates between what I call convergent and divergent forms of flexibility. Unlike divergent flexibility, which gives rise to contestation, convergent flexibility tends to promote consensus, even when technology is unprecedented and incentives to control it sharply diverge. To test the theory, I commission 450 legal professionals to take part in a randomized controlled trial (RCT) varying perceived technological novelty and legal precision. Participants collectively contributed 280,000 words over 10,000 hours in defense of their professional legal opinions, offering a novel (agent-subjective) measure of compliance. To demonstrate external validity, the experiment is complemented by primary source evidence on the legal impact of two breakthrough chemical weapons technologies—“super tear gas” and novichok. The findings contribute a general theoretical framework for understanding how law and technology interact.