Dissenting for career advancement: how Arbitrators use disagreement to increase their chances of appointment

Investor–state Dispute Settlement (ISDS) typically involves three-person panels of arbitrators who decide conflicts between foreign investors and host governments in relatively secretive deliberations. In contrast to other forms of adjudication, arbitrators in ISDS need not consider precedent, meaning that dissents are less important for shaping future jurisprudence. Dissents are also rare, occurring in fewer than 15 per cent of cases, but if dissents do not aim to influence the trajectory of law, what purpose do they serve? Arbitrators who dissent may risk their reputation for collegiality. Dissents can, however, serve as ideological signals that help garner future employment. This article considers the incentives for dissents and their impact on the subsequent career prospects of arbitrators. Our contributions to this literature are (i) to integrate the study of dissents in ISDS with a larger literature on dissents; (ii) to expand the data to multiple sets of arbitral rules, (iii) to investigate career possibilities other than serving again as an arbitrator, and (iv) to distinguish dissents according to which party they favour. Using a complete database of the known arbitrators from 1993 to 2022, we show that dissents improve the probability of reappointment as an arbitrator, but they reduce the probability of appointment as a chair/president of the panel and even as an attorney for the claimant. We argue that dissents serve to advertise partisan affinity in ISDS but at some cost to the career paths available to dissenters.