THE U.S. POSTAL Service reports a continuing decline in the number of dogs biting mailmen. The 1998 total of such attacks -- some 2,500 across the country -- was nearly two-thirds less than the average in the 1980s. The figures may be another indicator of a renascent trust in government among the American people -- or among the American whatever. But the evidence requires further study, and this cohort will be a particularly difficult one for social scientists and pollsters to analyze: Their focus groups tend to degenerate into pointless barking and snarling, while questionnaires will be returned in shreds, or simply eaten upon receipt, by the recipients.

Our guess -- and it's only a guess -- is that the reduced incidence of dog bites is due to the strong economy. No longer is the postman seen by Resident and Resident's Best Friend as someone who delivers bills, catalogues and dunning notices -- often to the wrong address. Now he is viewed as the deliverer of dividend checks, earnings reports and mail-order consumer goods -- often to the right address.

It could be deeper than this, of course. Maybe we are embarking on a new era that will see the end of the popular image of the mailman stolidly making his daily rounds with a growling terrier clamped on each ankle. But there are deep and ancient enmities at work here, and history tells us that these things often run in cycles. Peace could last a century, but it could also end in two or three years. To look on the bright side, though, that's still 15 or 20 dog years.