Judicial Treatment of Daubert Motions: An Empirical Examination


In 1993, the Supreme Court established a new standard for the admissibility of expert evidence with its decision in Daubert v. Merrell Dow Pharmaceuticals. Daubert, provided an interpretation of Federal Rule of Evidence 702 that replaced the “general acceptance” standard under Frye v. United States, with one that focuses on methodological rigor. Several studies have attempted to examine the extent to which Daubert has been an effective gatekeeper in purging “junk science” from the courtroom. Rather than attempting to measure impacts from Daubert, this study examines the way in which courts handle Daubert motions. Utilizing a sample of 2,127 Daubert motions made in 1,010 private civil federal district court cases from 2003-2014, and involving 57 different causes of action, this paper empirically examines how courts handle Daubert motions. The data suggest that Daubert rulings serve as inflection points in litigation, and that the longer a Daubert motion pends with the court, the lower the odds of settlement. Using a Cox proportional hazards model, I estimate that the relative odds of settlement is nearly ten-times lower for cases with median motion pendency times compared to those in the 10th percentile, and cases with pendency times in the 90th percentile are three times less likely to settle than those with median pendency durations. The apparent impact of Daubert rulings on case termination suggests that courts might reduce litigation time and costs if they were to adopt “Lone Pine”-type procedures that structure expert discovery and concomitant Daubert motions early, especially for claims that require expert testimony to prove certain elements.