Private Law Theory

ABSTRACT
Who leads in mass litigation? That question sits at the center of debate over multi-district litigation (MDL) – sprawling, consolidated proceedings that now account for a large share of federal civil litigation and play a pivotal role in responding to mass harms ranging from opioids to social media. At the heart of that debate sit plaintiffs’ leadership teams: court-appointed leadership groups, including plaintiffs’ steering committees (PSCs), that exercise extraordinary influence over investigation, strategy, settlement, and the distribution of recoveries.

However, the critical question of how MDL leadership is selected for these influential – and lucrative – roles has generated more heat than light. Critics, borrowing from antitrust, assert that MDL leadership operates like a cartel or oligopoly dominated by a small group of repeat players who suppress competition and entrench power. Defenders respond that repeat-play is a salutary way to tap the expertise, experience, and resources necessary to shepherd complex cases across finish lines. Resolving these competing assertions is central to assessing the legitimacy of the MDL regime and evaluating recurring calls for reform. And yet, despite the high stakes and a decade of debate, existing studies provide only the beginnings of an empirical foothold on who is selected, how often, and with what implications.

This Article provides the first systematic empirical analysis of plaintiffs’ leadership selection in MDL proceedings. Leveraging a novel dataset capturing every leadership appointment across more than two decades of MDLs, and supplementing that analysis with extensive interviews with practitioners, we offer the most comprehensive account to date of the market for MDL leadership. Our findings challenge prevailing narratives. Using conventional antitrust metrics, we find that MDL leadership is not highly concentrated and is marked by significant entry. And with respect to the tight collaboration at the heart of an individual MDL representation, we observe rates of co-appointment that are episodic rather than pervasive or inherently cartel-like.

All told, our findings suggest that cartelization is an inapt frame for understanding MDL leadership. But they do not vindicate the status quo. Our analysis reveals a system characterized by persistent stratification within the plaintiffs’ bar, substantial judicial delegation, and weak institutional constraints. Viewed through more appropriate lenses, MDL leadership selection functions less like an anticompetitive market and more like an ad hoc regime of public authority – one in which courts confer, supervise, and legitimate, through opaque and weakly articulated criteria, private actors to serve public statutory goals. By pushing past antitrust analogies and centering questions of capacity-building, representation, and accountability, this Article moves debate over MDL governance, and the identification of needed reforms, onto more fruitful terrain.

Bensouda Koraichi, Othman and Brundage, Matthew and Faria Bernardes, Gabriel and Engstrom, David Freeman and Hemphill, C Scott and Holland-Stergar, Brianne and Noll, David and Zimmerman, Adam S, Who Leads in Mass Litigation?: Evidence from MDL (August 14, 2026), 140 Harvard Law Review (forthcoming 2027).

See also: Bensouda Koraichi, Othman and Brundage, Matthew and Faria Bernardes, Gabriel and Engstrom, David Freeman and Hemphill, C Scott and Holland-Stergar, Brianne and Noll, David and Zimmerman, Adam S, Appendix to Who Leads in Mass Litigation?: Evidence from MDL (August 14, 2026).