Learning to Fly Without a Net: Inferring Legal Causation

• Activity Number: 104
• Type: Invited
• Date/Time: Monday, August 2, 2010 : 8:30 AM to 10:20 AM
• Sponsor: Section on Statistical Consulting
• Author(s): Herbert Weisberg*+
• Companies: Correlation Research, Inc.
• Keywords: bias ; observational studies ; litigation ; causation ; judgment

Abstract

Early in my consulting career, I regarded myself primarily as a technical expert, applying and extending sophisticated statistical methods. But the problems I encountered often did not fit neatly with this self-perception. I faced complex questions about causation, especially in the legal context. Addressing these required informed judgment. The relevant data and studies were primarily observational. So, my expert opinions had to account for potential sources of bias, as well as random variability. In the legal world, there is no "right answer" and no absolute principle like randomization to assure legitimacy. In this sometimes stressful but also exhilarating environment, I learned that a statistical expert can make a real difference, but not exactly in the ways I had originally imagined. Actual cases will illustrate the challenges and opportunities.