In: Economics
It shall be noted that Disparate impact refers to practices in employment, housing, and other areas that adversely affect one group of people of a protected characteristic more than another, even though rules applied by employers or landlords are formally neutral.
It shall further be noted that disparate impact is not, in and of itself, illegal. It becomes illegal if the employer cannot justify the employment practice causing the adverse impact as a "job related for the position in question and consistent with business necessity" (called the "business necessity defense").
For example - The fire department requiring applicants to carry a 100 lb (50 kg) pack up three flights of stairs. The upper-body strength required typically has an adverse impact on women. This results in disparate impact. This condition could be used to hold the fire department liable for "discriminating" against female job applicants.