Expert Histories

This study arises from the basic idea that an expert's admissibility record may have downstream effects. Most notably in recent years, courts appear to cite previous admissions or exclusions in deciding whether to admit or exclude an expert. In addition, anecdotally, experts have expressed fear that even a single exclusion can negatively impact their future ability to testify (and therefore their future livelihood as a testifying expert). This study, part of a broader paper on expert histories, attempts to em- pirically test whether an expert's probability of exclusion is constant, or whether previous exclusions negatively affect an expert's chances of being admitted in future cases. It also asks whether previous exclusions negatively affect an expert's chances of being retained in the future. To do so, the study uses an existing database on expert history compiled and maintained by Expert Profi?ler, LLC. Expert Profi?ler is a consulting service typically hired by litigants to research the prior admissibility records of experts. Their database contains the results of these consulting efforts, which scour the public record (and not just the published case law) for previous pro?ers and challenges of selected experts. The paper uses both a newly developed method for discrete-time recurrence analysis as well as more conventional discrete-time survival analysis.