Two Faces of Causality: A Small Case Study of the Admission of Scientific Evidence to Show Causality in a Bias and a Toxic Tort Case in the 4th Circuit Christina Kirk Pikas LBSC 735: Legal Issues in Information Management December 11, 2002

Overview Review of the efforts made to form the admissibility of scientific evidence Review of the efforts made to form the admissibility of scientific evidence Discussion of causality and the scientific and the statistical methods used to prove Discussion of causality and the scientific and the statistical methods used to prove Case studies of two cases: Case studies of two cases: Product liability Product liability Pay discrimination Pay discrimination

Admission of Expert Evidence 19 th century 19 th century Frye (1923) Frye (1923) Federal Rules of Evidence (1975) Federal Rules of Evidence (1975) Daubert Trilogy Daubert Trilogy Daubert (1993) Daubert (1993) Joiner (1997) Joiner (1997) Kumho (1999) Kumho (1999)

Causality Definition: “The principle of causal relationship; the relation between cause and effect” (Black’s Law Dictionary) Definition: “The principle of causal relationship; the relation between cause and effect” (Black’s Law Dictionary) Cause: “To bring about or effect” (Black’s Law Dictionary) Cause: “To bring about or effect” (Black’s Law Dictionary) Correlation, association, or statistically significant relationship is not enough Correlation, association, or statistically significant relationship is not enough Primary issue in Primary issue in Toxic torts Toxic torts Product liability Product liability Discrimination Discrimination

General vs. Specific Causality General (examples: toxicology, epidemiology) General (examples: toxicology, epidemiology) anecdotal evidence anecdotal evidence observational studies observational studies controlled experiments controlled experiments Specific Specific Treating Doctor Treating Doctor Series of specific details such as Series of specific details such as Biological plausibility Consideration of alternate hypotheses Cessation of exposure Temporal relationship Strength and specificity of association Dose-response relationship Consistent with other knowledge

Case 1: Nettles v. Proctor & Gamble Ms. Nettles used Vicks Sinex Nasal Spray and later became blind Ms. Nettles used Vicks Sinex Nasal Spray and later became blind A neuro-opthalmologist was produced to give evidence on her case A neuro-opthalmologist was produced to give evidence on her case No studies existed linking the main ingredient to her condition No studies existed linking the main ingredient to her condition Only temporal connection was found Only temporal connection was found As per Joiner – court did was neither arbitrary or capricious, decision was affirmed As per Joiner – court did was neither arbitrary or capricious, decision was affirmed

Case 2: Smith, et al v. Virginia Commonwealth University VCU employed a committee to determine if there was a discrepancy in pay between male and female tenure and tenure-track professors VCU employed a committee to determine if there was a discrepancy in pay between male and female tenure and tenure-track professors The committee used a multiple regression analysis and determined that there was a $1,300 difference. Another committee was started to review CVs and give deserving female employees appropriate raises. The committee used a multiple regression analysis and determined that there was a $1,300 difference. Another committee was started to review CVs and give deserving female employees appropriate raises.

Case 2: continued Plaintiffs Allege Plaintiffs Allege Not fair because raises based only on gender Not fair because raises based only on gender Inflated pool – more males had been administrators and therefore had higher pay Inflated pool – more males had been administrators and therefore had higher pay Analysis not valid because did not take into account major factors relating to pay, namely performance Analysis not valid because did not take into account major factors relating to pay, namely performance Trial Court Trial Court Proxies were sufficient, regression study valid, pay handed out fairly, to correct inequity Proxies were sufficient, regression study valid, pay handed out fairly, to correct inequity Summary Judgment awarded to VCU Summary Judgment awarded to VCU

Case 2: Continued Appeals Court Appeals Court Regression did not take into account performance factors, not invalid, but probative value in question Regression did not take into account performance factors, not invalid, but probative value in question If material issues exist, should not have been a Summary Judgment, reversed. If material issues exist, should not have been a Summary Judgment, reversed. Analysis Analysis If the lower court had employed Daubert factors, the summary judgment was correct If the lower court had employed Daubert factors, the summary judgment was correct The initial study was invalid – it poorly fit the real situation under study The initial study was invalid – it poorly fit the real situation under study

Conclusion Complexity of new cases, commingling of evidence, junk science make the gatekeeper role very important Complexity of new cases, commingling of evidence, junk science make the gatekeeper role very important Judges see expert evidence 90 days before trial Judges see expert evidence 90 days before trial Many courses, books, and studies exists to help train judges Many courses, books, and studies exists to help train judges Judges can appoint neutral experts to help interpret the evidence Judges can appoint neutral experts to help interpret the evidence

More Conclusions Scientific methods and statistics are being used for purposes for which they were not designed Scientific methods and statistics are being used for purposes for which they were not designed Statistics don’t prove anything – give relative probability Statistics don’t prove anything – give relative probability Toxicology and epidemiology – give relative risk Toxicology and epidemiology – give relative risk Statistical significance and practical significance are not the same Statistical significance and practical significance are not the same

Finally Daubert provides a useful framework if flexibly employed Daubert provides a useful framework if flexibly employed Resulting summary judgments save time and money Resulting summary judgments save time and money It’s still easy to lie with statistics It’s still easy to lie with statistics