ONE COULD GO on. There is an "official estimate" of the rat population of New York (8 million) extracted from an accommodating official there nearly 20 years ago and sanctified through unchanging repetition not only by that city's press but in Time, Newsweek, The Wall Street Journal and speeches on the floor of Congress.

In many such cases, to be sure, there is the protective disclaimer. "While it may be too early for the experts to compute the precise cost of . . ." or "Nobody outside the Mafia knows the full extent of their operations, but . . ." are typical formulations. But the disclaimer as often as not is framed in such a way that the chief impression it leaves is not so much of the imprecision of the number to follow as the likelihood that - if you really hit it on the nose - the number might be still larger.

Most of the eye-popping numbers cited here have no particular ideology. Their function is essentially to hype a story - to suggest that the subject is very important, unprecedented or otherwise memorable. And, when the story is competitive, bonuses are seldom awarded for having the lowest numbers.

In this respect the routine press pursuit of the biggest number, or sometimes any number, is a different case from that classic of press criticism, the "Rubber Type Army" of Chiang Kai-shek, immortalized by A.J. Liebling, whose numbers waxed and waned in keeping with the source's - or the paper's - fury over President Truman's refusal to unleash them. Nor is it like such currently tendentious figures as the number of Cubans in Ethiopia, MIRVs in Russia or people on the White House staff.

Such numbers are generally volunteered by sources with a stake in a dispute. They carry their own warning flag, are apt to be dealt with warily in the first instance and responded to quickly by other parties in the dispute.

The contrasting case is where the press and officialdom, or "experts," or the passive "it" (as in "it is estimated that") are the joint parents of some proud and towering figure. When reporters press a bureaucrat who doesn't have the foggiest idea for the dollar cost of a riot still in progress, for the number of potholes left by yesterday's snowstorm, for a census of the rats or closet deviates or people watching a motorcade or the earnings of anything so ill-defined (and tight-lipped) as organized crime, they are collaborating in their own deception.