We were leaving a pre-Christmas party at the home of a young black couple, gaping at the exquisitely tailored men, the fur-draped women, the Mercedes Benzs and BMWs and at least one chauffered Rolls Royce. "Black folk," said an admiring friend, "are doing all right."

Hours later, I am reading John Reid's report on "Black America in the 1980s," mulling over his somber conclusion that black folk are not doing very well, and may shortly be doing a good deal worse.

Both observations are accurate, More black professionals are making more money, living better, more solidly in the mainstream than some of us could have imagined a decade or two ago. Reid, a Howard University sociologist, acknowledges as much:

"Occupational gains for black American workers were truly remarkable in the 20 years after 1960. By 1980, some 40 percent were in white-collar occupations compared to 54 percent for whites, and fower than 2 percent were farm workers versus nearly 3 percent among the white employed. The proportion in craft occupations (9.6 percent) was approaching that of whites (13.3 percent)."

But his study offers another set of figures. Median black family income was 57 percent of white family income in 1960. By 1970, it was 61 percent. According to the latest figures, for 1981, it was 56 percent. More black families (30.8 percent) were living in officially defined poverty than at any time since 1968, when the rate was 33.9 percent. During that same period, white poverty rates dipped slightly from 9 percent to 8.8.

Reid's striking conclusion: "On the non-monetary side, that is, in education and occupation, blacks have made significant progress in the past two decades; on the monetary side -- income -- blacks have made no gains and indeed appear to be falling somewhat behind in their quest for equality."

Maybe that it is a temporary phenomenon, attributable to the sad state of the American economy. And maybe it isn't.

Reid points to three factors that suggest that blacks may be in for more rough times. One is that well over half of the black babies born today are born out of wedlock, many of them to adolescents, which suggests that they will grow up with problems that negatively affect their educational and, therefore, their employment prospects. A second is the "surge of legal and illegal immigrants and refugees, no longer white Europeans but primarily Hispanics and Asians, [that] presents new competition for black Americans just as they have finally begun to edge up the socioeconomic ladder." Third, blacks, most likely to be first-fired because they were last hired, will have trouble finding new work in hightech industry when their old jobs disappear.

These things, says Reid, threaten to produce "an even larger and more permanent underclass within the black population. It is this which needs immediate and urgent attention if blacks are to join the mainstream of American society."