A Moving Bar Approach to Assessing the Admissibility of Expert Causation Testimony

This Article argues that the Supreme Court\u27s decisions in Daubert and Joiner imply an approach to the reliability, and hence admissibility, of causation experts that conflicts with the way in which courts traditionally had determined whether to allow the jury to speculate on uncertain causation-in-fact questions. Largely moving past the debate of whether Daubert and Joiner set the admissibility bar too high or low, the Article instead criticizes the decisions on the ground that they suggest that the height of the reliability bar is static and should not be adjusted depending upon the circumstances of the defendant\u27s possibly injurious conduct. Under the “all-or-nothing” liability rule, the exclusion of a plaintiff\u27s expert causation evidence will necessarily result in under-deterrence. Conversely, the admission of a plaintiff\u27s questionable expert will necessarily expose a defendant to potential liability for harm that, from a probabilistic perspective, it did not cause. This Article thus critiques the static bar approach from a deterrence perspective and argues that the nature of the defendant\u27s conduct should be a factor in a court\u27s determination of whether a plaintiff\u27s causation expert\u27s proffer is sufficiently reliable to warrant admission at trial