An uncertain future for black Americans.

In the near future, rising numbers of black Americans will attain high-status occupations and political positions, but a sizable minority of blacks will remain impoverished. This mixed forecast comes from an authoritative National Research Council report on the changing status of black Americans

Over the 50-year period covered by the study, the status of black Americans has on average improved dramatically. Yet, one-third of the black population - and nearly half of all black children - still live in poverty. A major impediment to black progress has been the slow overall growth of the economy during the 1970s and 1980s, according to the report. Economic prosperity and rapid growth from the 1940s through the 1960s had been a great help to most blacks.

Barring significant policy changes, the report predicts several negative developments for blacks in the near future:

The rate of increase of the black middle class is likely to decline, although a substantial majority of black Americans will remain productive citizens.

Approximately one-third of the black population will continue to be poor, and the relative employment and earnings status of black men, now declining, is likely to deteriorate further.

Drugs and crime, teenage parenthood, poor education, and joblessness will maintain their grip on large numbers of poor and near-poor blacks.

High rates of residential segregation between blacks and whites will continue.

The United States faces the prospect of continued great inequality between whites and blacks and a continuing division of social status within the black population.

These short-term projections have important implications for the future well-being of the United States, notes the report. The Bureau of the Census projects that the black population will increase from 11. 7% of the U. S. total in 1980 to 15% in 2020; blacks will be nearly one of five children of school age and one of six adults of prime working age (25-54). Source: A Common Destiny: Blacks and American Society, edited by Gerald D. Jaynes and Robin M. Williams jr. for the Committee on the Status of Black Americans, National Research Council. National Academy Press, 2101 Constitution Avenue, N.W., Washington, D.C. 20418. 1989. 608 pages. $35.