Multidistrict Centralization: An Empirical Examination

Following the judiciary's experience with aggregate litigation in the 1960s, Congress established a procedure for the transfer of related cases to a single district court for coordinated pretrial proceedings. Originally designed to achieve efficiencies associated with coordinated discovery, the multidistrict litigation (MDL) process evolved from a rather modest starting point to become a central part of aggregate litigation in the federal courts today. Despite its importance, however, there is little empirical research on the MDL process. This article seeks to fill this gap in the empirical literature by addressing a few central questions about the work of the Judicial Panel on Multidistrict Litigation (Panel). Using a unique database, we examine how that body decided motions to centralize multidistrict litigation. We find, most importantly, that the Panel became more likely to order centralization of proceedings over time, after controlling for other factors. That trend is not, however, apparent in the most recent years' data. We also find, all else equal, that the Panel is more likely to centralize a proceeding including class allegations, and more likely to centralize proceedings raising certain kinds of claims.