Lack of reliability continues to be the main reason for financial expert witness exclusions under Daubert, according to the PwC survey, “Daubert Challenges to Financial Experts.” The annual study analyzes challenges to financial expert witnesses (appraisers, accountants, economists, and others) under the Daubert standards from 2000 to 2018. These are the years following the U.S. Supreme Court’s Kumho Tire decision, which expanded Daubert’s reach to financial expert witnesses. Exclusions most commonly result from the lack of sufficient data or the use of methods that are not generally accepted, the study says.