In Do Lawyers Really Believe Their Own Hype and Should They?: A Natural Experiment, Zev Eigen (Northwestern) and Yair Listokin (Yale) cleverly exploit a ready natural experiment (student moot court competitions) to control for self-selection that limits most studies of lawyers' confidence in the legal merits of their clients' positions. The abstract follows.
"Existing research suggests that practicing litigators are too confident in the merits of their clients’ cases. But practicing attorneys often self select (1) the area of law in which they practice, (2) the side on which to practice within that area, (3) law firms with whom they practice, and (4) the clients they represent. We explore whether, after stripping away these selection-biases, legal advocates are still overconfident in their clients’ claims by exploiting a natural experiment involving participants in moot court competitions at three U.S. law schools. Students are randomly assigned to advocate for either petitioner or respondent, so none of the selection-bias problems above are present. We find that following participation in moot court contests, students overwhelmingly perceive that the legal merits favor the side that they were randomly assigned to represent. We also find that overconfidence is associated with poorer performance in advocacy as measured by legal writing instructors. Theoretical and practical implications are discussed."