Two Experts Discuss Our 'Disparate Impact' Post

Statistics, competing interests, job-relatedness and business necessity — all this and more from two experienced attorneys who have provided invaluable commentary on our post this week on "disparate impact" discrimination.

We wrote that "While courts have often held that although a standardized test may be neutral and non-discriminatory on its face, and therefore demonstrate no discriminatory intent, nonetheless the impact of such a test may disproportionately fall upon members of a protected class, and therefore be found to be discriminatory."

Our experts weigh in:

Daniel Kinsella, an attorney in the Chicago area:

"Richard, first, thank you for identifying "disparate impact" as "unintentional discrimination." That, I believe, is a very important distinction with "disparate treatment" cases. We must go back to Griggs v. Duke Power to understand the statutory basis for such claims of unintentional discrimination.

Second, statistics are too often misunderstood and misused, even in litigation. You toss around the term "statistically significant" like a throw-rug. Since I, like most lawyers, slept through at least one statistics course as an undergraduate, arguing something is or is not "statistically significant" requires a statistician, i.e., someone who actually took more than one statistics course, stayed awake and really enjoyed it. (That was the guy, or girl, you went to get class notes when you slept through yet another class; thick glasses, pocket protector, slide-rule — showing my age — or calculator on a holster on the belt.)

A statistician can interpret and analyze the data and determine how far off the median (or mean) a given distribution is. That distance is the number of standard deviation units.

In short, a high percentage difference between numbers does not automatically make a "statistically significant" difference. Conversely, a low percentage difference does not automatically translate to no statistical significance. Other factors, such as sample size, are important. Back of the envelope math doesn't cut it."

Richard Seymour, an attorney in the Wash., D.C. area:

"This is a useful posting. For much of my professional life, I've prosecuted disparate-impact cases. Once the practice is identified and its impact shown — both sometimes very difficult — the focus turns to the question whether the practice is job-related and consistent with business necessity.

For example, police hiring tests used to be reading comprehension tests...