Be sceptical when claims are made that a law like this will boost elderly employment. Between 1984 and 1994, as age-bias suits boomed here, labor force participation for the key target group, men aged 55-64, slid from 68.5 to 65.5 percent; it has since recovered, but only back to the old level.

Some believe the climate for older jobseekers has in fact gotten worse. Once managers learn to avoid verbal slips, it’s actually quite hard for a lone rejected applicant to prove an age-bias case. And there’s scant pressure on employers to "hire by numbers", since no one seriously argues that a set share of new lifeguards, bicycle messengers or MTV hosts should sport silver hair. At the same time, if you do give sixtyish applicants a try and they don’t work out, they may bring suit or require an expensive buyout.

Yes, age-bias law in the US probably counts as politically unassailable. But that doesn’t mean it has worked well.

Walter Olson edits Overlawyered.com and PointOfLaw.com and is a senior fellow at the Manhattan Institute. For more on age-bias law in the US, see his book The Excuse Factory (Free Press, 1997).