Erie and the Rules of Evidence
Cheng, Edward K.
Jay Tidmarsh offers an intriguing new test for drawing the allimportant line between procedure and substance for purposes of Erie. The Tidmarsh test is attractively simple, yet seemingly reaches the right result in separating out truly “procedural” rules from more substantive ones. Since I am not a proceduralist, in this Response I will leave the Tidmarsh test’s explanatory power and practical workability vis-à-vis general civil procedure rules to others more qualified than I. Instead, I want to focus on the implications of the Tidmarsh test for the Federal Rules of Evidence. Like others in the evidence world, I have long harbored concerns about a potential conflict between Erie and Daubert because of Daubert’s profound impact on toxic tort cases.2 Professor Tidmarsh’s article offers an opportunity to revisit this concern, as well as a chance to think broadly about the relationship between Erie and evidentiary rules.