NOW DISCONCERTINGLY, the unemployment rate has actually dropped a little. Even since last spring the country has been anxiously debating whether it is in a recession. The performance brings to mind the hypochondriac who keeps taking his temperature to see how he ought to be feeling. The evidence still indicates that, yes, there's a real recession coming -- but no, it probably won't be severe.

The special significance of the November unemployment rate is that it's the last one before the White House makes the final decisions on the three midwinter messages; when the next number arrives, it's too late for changes. First comes the State of the Union address, then the budget, then the economic report. If the November unemployment figures, published Friday, had suddenly lurched upward, the messages would have required some hasty last-minute insertions regarding the possibility of future tax cuts, the need to preserve flexibility, and so forth. With a falling rate, even though everyone knows that it won't last, the president has the opportunity to speak to the subjects of inflation and energy without that distraction. In this respect, as in every other, the November numbers are very good luck. The case for a reduction in taxes for 1980 is far from clear. President Carter has held for months that discussion of it from the White House only creates a diversion from larger and more urgent questions.

The unemployment rate in mid-November, the federal computer reports, was 5.8 percent of a labor force that is now just over 100 million Americans. Would you call that rate high or low? Throughout most of the past generation 4 percent was the conventional idea of full employment -- the minimum below which employers begin bidding against each other for labor and offering inflationary wage increases. But in the 1970s that point shifted rapidly upward. Currently, it seems to be nearly 6 percent -- just about where it was last month.

Perhaps this kind of an unemployment level, high by past standards, will turn out to be characteristic of a society that is affluent and highly education, in which it is common for more than one person in a family to work. As people become more highly trained for specialized lines of work, they speed more time looking for precisely the right job. In a prosperous country they can afford it. Fewer people are forced to take the first job that comes along -- and that's an important social benefit.

The November survey was made before most of the recent layoffs in the steel and automobile industries. The next few month's rates aren't likely to be quite so cherry. But employment has been holding up remarkably well in an uncertain time. The genuinely dangerous economic challenges this winter, like last winter, are going to be inflation and the oil supply.