In its 7-1 ruling with one justice not participating, the court overturned a federal appeals court ruling that said employees bore the burden of proof to invalidate an employer's claim of using factors other than age in layoff decisions. The case was remanded to the U.S. Court of Appeals for the Second Circuit
"An employer defending a disparate-impact claim (under the Age Discrimination in Employment Act) bears both the burden of production and the burden of persuasion for the 'reasonable factors other than age,'" the court held.
When the federal government ordered Knolls Atomic Power Laboratory to reduce its work force, the government contractor -- using a scoring system developed by its managers -- furloughed 31 employees, 30 of whom were at least 40 years old. Twenty-eight of them sued under the ADEA, which provides protections to employees over 40.
"Congress took into account the distinctive nature of age discrimination and the need to preserve a fair degree of leeway for employment decisions with effects that correlate to age" when it included the "reasonable factors other than age" clause in ADEA, the majority opinion by Justice David Souter said.
"Whether the outcome should be any different when the burden is properly placed on the employer is best left to that court in the first instance," Souter said.
Justice Antonin Scalia wrote a concurring opinion. Justice Clarence Thomas dissented. Justice Stephen Breyer did not participate.