Expert Article Library

Statistical Method With Error Upheld in Vote Dilution Case

Case Name: Bone Shirt v. Hazeltine (Click here for the full text of the case)

Court: 8th Circuit Court of Appeals

Date: August 22, 2006

Expert: Statistical expert. Dr. Steven Cole, PhD

Issue: Whether Cole’s statistical method was reliable?

Summary of case: Native Americans brought a vote dilution claim alleging improper 2001 legislative re-districting designed to deny Native-Americans the opportunity to elect Indian preferred candidates.

Role of the expert: Dr. Steven Cole performed bivariate ecological regression analysis (“BERA”) and homogenous precinct analysis (“HPA”) to determine the effect of the districting.

Challenges to the Expert's testimony: Defendant disputed the relevance and reliability of Dr. Steven Cole’s expert testimony relying on the BERA and HPA tests. The defense expert employed the ecological inference (“EI”) method and argued that this was the acceptable test. The court ruled that the “statistical methods used by the plaintiffs have long been accepted by the Supreme Court and other courts.” The court noted that the results from all of the experts in the case were very similar. This helped to mitigate the fact that Cole admitted to having an error in his method that resulted in unknown effects. The Court of Appeals held that the District Court properly admitted the expert testimony.

Summary prepared by M. Lanzone, Student, University of California, Hastings College of Law