On Sept. 1, a federal judge ordered an end to 26 years of busing meant to achieve racial desegregation in Prince George's County, Md., public schools. The decision, which tracks similar rulings nationally, is being widely heralded as a triumph of common sense. Democrats and Republicans alike -- even the supposedly liberal Washington Post -- are applauding the movement back to neighborhood schools.

From the strict racial lens of the Supreme Court's Brown vs. Board of Education decision, busing in Prince George's County looks, and is, absurd. The county school system is now 75% black, and busing often involves transportation of black students from one part of the county to be with black students in other parts of the county.

But amidst the celebration, it is important to note that one group is likely to be hurt by the end of busing: the county's poor blacks living inside the capital Beltway.

The Prince George's case raises in stark form a new question: As the demographic, legal and psychological underpinnings of Brown erode, what can and should be done to address the increasing economic isolation of the nation's poorest students? Such is the new frontier of school desegregation.

The pitfalls of high-poverty schools

Even within racial groups, there are large economic divides, and one of the hidden but significant benefits of busing in Prince George's County in recent years has been the integration of some black students across class lines. According to The New York Times, part of the impetus to end busing was a desire on the part of middle-class black communities to keep poor blacks out of their schools.

In Prince George's County, the phrase "inside the Beltway" has a different meaning than it does nationally, and wealthier black communities outside the Beltway frequently have clashed with poorer blacks inside.

From a legal standpoint, no federal law supports class-based integration. Under Brown, what matters is racial balance, not class balance. But from a social science standpoint, it is class, much more than race, that matters.

James Coleman's landmark 1966 study on equal opportunity found that black students did better on average in integrated schools. But the "beneficial effect of a student body with a high proportion of white students comes not from racial composition per se but from the better educational background and higher educational aspirations that are, on the average, found among whites," he wrote.

Blacks do not need to sit next to white students in order to learn, but a number of studies find students from poor families are much more likely to excel in predominantly middle-class schools than schools populated by large numbers of poor peers. Now, with an end to busing in Prince George's County, and the return to neighborhood schools, the residential segregation by class within the black community will be more fully reflected in the schools, and poor black students are more likely to attend high-poverty schools.

Under the settlement approved by U.S. District Judge Peter J. Messitte, Prince George's County schools will receive an influx of state aid as busing comes to an end, and some of this money no doubt will benefit the education of poor black students. But the other major finding of the Coleman Report, which still stands today, is that classmates matter more than money to educational achievement.

More money is not the answer

Coleman found that "the educational resources provided by a child's fellow students are more important for his achievement than are the resources provided by the school board." Recent studies in San Francisco and Norfolk confirm that similarly situated students do better in economically integrated schools with less funding than in segregated schools that receive extra funding.

We know in the public housing field that concentrations of poverty are a recipe for disaster. And in the education arena, parents know the socio-economic makeup of a school is crucial. Most parents would rather send their children to schools with a strong middle-class environment that spends somewhat less per pupil than to a high-poverty school that spends somewhat more.

Statistically speaking, middle-class schools are much more likely to provide a student environment where achievement is highly valued, parents are actively involved and the best teachers are found.

As a matter of federal law, little can be done to address economic school integration in Prince George's County or elsewhere because Brown and its progeny speak to race only. Nationally, however, there is some hope that state constitutions can be used to achieve economically integrated schools.

In many states, the constitution has been read to require equal educational opportunity. So far, that principle has been largely applied to require equal spending. But because fellow students matter even more than per-pupil expenditure to the promise of equal opportunity, a strong legal argument can be made on behalf of breaking up concentrations of poverty, and increasing the number of students who attend schools that are majority middle class.

Politically, the movement toward greater public-school choice and charter schools can be harnessed to ensure they promote, rather than diminish, socio-economic integration. Nationally, about one-fifth of students are poor, so majority middle-class schools are not difficult to create, particularly when interdistrict plans are employed.

Why 'separate' is still not equal

The end to busing in Prince George's County could mark a turning point in the way we view school desegregation. The question of racial integration has been played out, to disappointing results. But the larger questions of economic integration remain to be addressed.

If we are to provide genuine equal opportunity to students, our law and public policy must grapple with ways of restoring the common public school that brings together people of all different economic backgrounds.

So long as we tolerate separate schools for the poor, we will not fully realize America's distinctive democratic promise of social mobility and national cohesion.

Richard D. Kahlenberg, a fellow at The Century Foundation, is writing a book about economic desegregation of the public schools.