(FORTUNE Magazine) – In his outstretched hand, Keeping Up's senior policy analyst brandished a now-empty library folder labeled ''AGED, United States, Discrimination, 1980 -- .'' Piled around his ankles was a three-inch-high heap of clippings, eloquent testimony to the immensity of the research effort thus far. In the man's voice was a steely determination. ''Kindly query the library one more time,'' he adjured, ''as we are maximally loath to accept that with all the Mergenthaler Linotypes at its disposal the press still cannot produce a single news story dealing realistically with 'ageism,' a word that only a Gray Panther could love but there it is in all the dictionaries, along with 'ageist,' which is something we might well turn into if we could only figure out where to sign up.'' A point infrequently made about ageism is that it tends to make a lot of economic sense. The principal point of our existing laws against age discrimination is to override economics. You would never learn that, however, from the heap on our floor, in which the modal story was about an age- discrimination suit brought by awesomely competent albeit no longer upwardly mobile professionals against a company that knew not its own best interest and was tilting toward youngies. That managers are blinded by stereotypes and do not know their true interests as well as the nearest politician does was an idea central to the 1967 Age Discrimination in Employment Act (ADEA), under which the EEOC last year received 16,784 complaints. Although bad enough at the outset, ADEA has since been disimproved substantially. In numerous circumstances, it is now not necessary for the plaintiff to prove that the managers are biased; as in other corners of antidiscrimination law, it is now sufficient to establish that some company policy has a ''disparate impact'' on the oldies. Disparate-impact reasoning has a big effect on many companies because old folks and young folks are different kinds of employees. The old folks are far more likely to have vested pension rights, for example. They're also more likely to have higher pay on average. So an employer trying to make purely economic decisions about different kinds of employees can easily commit ageism. If he has to cut back the workforce, he is an ageist if he decides to lop off those who will be cushioned by pensions, as various circuit courts of appeal have been ruling in recent years. In finding for the EEOC against the Altoona, Pennsylvania, Fire Department, Judge John J. Gibbons of the Third Circuit composed a sentence that says it all. ''The City's contention that the retirements were based on economic considerations is . . . meritless,'' he opined, ''for such considerations cannot be used to justify age discrimination.'' In other words, rational behavior is verboten. We got interested in the trajectory of ADEA law recently as the result of reading about Howard Metzenbaum's hysterics in the Senate Labor Committee, Howard being scared that the EEOC might change its views if Zuckerman came to power. Jeffrey Ira Zuckerman, who has has been nominated to be general counsel of EEOC, seems to think it is perfectly reasonable and in fact humane for a company laying off people to mostly target those with pension rights, and also reasonable for the EEOC to back away from disparate impact. Whether his views will prevail is still uncertain, but they are definite losers in this pile below the shinbone.