Lawyer and Economist Expert Witnesses Fail the t-Test

Chad L. Staller is a lawyer and James Markham is an economist.  The two testify frequently in litigation.  They are principals in a litigation-mill known as the Center for Forensic Economic Studies (CFES), which has been a provider of damages opinions-for-hire for decades.

According to its website, the CFES is:

“a leading provider of expert economic analysis and testimony. Our economists and statisticians consult on matters arising in litigation, with a focus on the analysis of economic loss and expert witness testimony on damages.

We assist with discovery, uncover key data, critique opposing claims and produce clear, credible reports and expert testimony. Attorneys and their clients have relied on our expertise in thousands of cases in jurisdictions across the country.”

Modesty was never CFES’s strong suit. CFES was founded by Chad Staller’s father, the late Jerome M. Staller, who infused the run-away inflation of the early 1980s into his reports for plaintiffs in personal injury actions. When this propensity for inflation brought in a large volume of litigation consulting, Staller brought on Brian P. Sullivan.  The CFES website notes that Sullivan’s “courtroom demeanor was a model of modesty and good humor, yet he was known to be merciless when cross examined by an opposing attorney.” My personal recollection is that Sullivan sweated profusely on cross-examination. In one case, in which I cross-examined him, Sullivan had added several figures incorrectly to the plaintiff’s detriment.  My cross-examination irked the trial judge (Judge Dowling, who was easily irked) to the point that he interrupted me to ask why I was wasting time to point out an error that favored the defense. The question allowed me to give a short summation about how I thought the jury might want to know that the witness, Sullivan, had such difficulty in adding uncomplicated numbers.

In Butt v. v. United Brotherhood of Carpenters & Joiners of America, 2016 WL 3365772 (E.D. Pa. June 16, 2016) [cited as Butt], plaintiffs, women union members sued for alleged disparate treatment, which treatment supposedly caused them to have lower incomes than male union members. To support their claims, the women produced reports prepared by CFES’s Chad Staller and James Markham. Counsel for the union challenged the admissibility of the proffered opinions under Rule 702. The magistrate judge sustained the Rule 702 challenges, in an opinion that questioned the reliability and ability of the challenged putative expert witnesses.[1]

Staller and Markham apparently had proffered a “t-test,” which, in their opinion, showed a statistically significant disparity in male and female hours worked, “not attributable to chance.” Butt at *1. Staller and Markham failed, however, to explain or justify their use of the t-test.  The sample size in their analysis included 17 women and 388 men on average across ten years. The magistrate judge noted serious reservations over the CFES analysis’s failure to specify how many men or women were employed in any given year. Plaintiffs’ counsel improvidently attempted to support the CFES analysis by adverting to the Reference Manual on Scientific Evidence (3d ed. 2011), which properly notes that the t-test is designed for small samples, but also issues the caveat that “[a] t-test is not appropriate for small samples drawn from a population that is not normal.” Butt at *1 n.2. The CFES reports, submitted without statistical analysis output, apparently did not attempt to justify the assumption of normality; nor did they proffer a non-parametric analysis.

Putting aside the plaintiffs’ expert witnesses’ failure to explain and justify its use of the t-test, the magistrate judge took issue with the assumption that a comparison of average salaries between the genders was an appropriate analysis in the first place. Butt at *2.

First, the CFES reports assigned damages beyond the years used in their data analysis, which ended in 2012. This extrapolation was especially speculative unwarranted given that union carpenter working hours were trending downward after 2009. Butt at *3. Second, and even more seriously, the magistrate judge saw that no useful comparison could be made between male and female salaries without taking into account several important additional variables such as their individual skills, the extent that individual carpenters solicited employment, or used referral systems, or accepted out-of-town employment. Butt at *3.[2] Without an appropriate multivariate analysis, the CFES reports could not conclude that the discrepancy in hours worked was caused by, rather than merely correlated with, gender. Butt at *4.[3]


[1] See Calhoun v. Yamaha Motor Corp., U.S.A., 350 F.3d 316, 322 (3d Cir. 2003) (affirming exclusion of “speculative and unreliable” expert evidence).

[2] citing Stair v. Lehigh Valley Carpenters Local Union No. 600 of United Brotherhood of Carpenters and Joiners of America, No. Civ. A. 91-1507, 1993 WL 235491, at *7, *18 (E.D. Pa. July 24, 1993) (Huyett, J.), aff’d, 43 F.3d 1463 (3d Cir. 1994) (“Many variables determine the number of hours worked by a carpenter: whether the carpenter solicits employment, whether he or she uses the referral system, whether an employer asks for that carpenter by name, whether the carpenter will accept out of town employment, and whether the carpenter has the skills requested by an employer when that employer calls the Union for a referral.”

[3] Interesting cases cited by the magistrate judge in support included Molthan v. Temple University, 778 F.2d 955, 963 (3d Cir. 1985) (“Because the considerations affecting promotion decisions may differ greatly from one department to another, statistical evidence of a general underrepresentation of women in the position of full professor adds little to a disparate treatment claim.”); Riding v. Kaufmann’s Dep’t Store, 220 F.Supp. 2d 442, 459 (W.D. Pa. 2002) (“Plaintiff’s statistical evidence is mildly interesting, but she does not put the data in context (how old were the women?) [or] tell us what to do with it or what inferences should be gathered from it…”); Brown v. Cost Co., No. Civ. A. 03-224 ERIE, 2006 WL 544296, at *3 (W.D. Pa. Mar. 3, 2006) (excluding statistical evidence proffered in support of claims of disparate treatment).

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