Two former presidents of Harvard and Princeton universities claim in a new book to have exploded the "myths" that have fuelled a United States backlash against preferences for racial minority students.
Drawing on "a massive new database" of the lives and careers of 45,000 students, Derek Bok and William Bowen claim to prove that affirmative action has been of huge help for its black American beneficiaries and society at large.
Black students whose race helped them gain admission to top-flight universities have become the backbone of a black middle class by taking high-paid jobs and often going on to graduate and professional degrees, the book says.
Conservative critics were already taking aim this week at The Shape of the River. But its authors hope it will bring some "hard facts" to bear on what is a highly charged debate. Affirmative action programmes - in which ethnic minority students, particularly black and Latino, are given preferences in the admissions process - have been rolled back in Texas and California by legal and political challenges.
At the same time, precipitous drops in the enrolment of blacks and Hispanics at institutions such as the University of California at Berkeley have left university presidents looking for ways to keep these minority numbers up - even as their college entry exam scores remain stubbornly lower than their white and Asian contemporaries.
The authors are prominent members of a US education establishment that has largely embraced affirmative action in the past three decades. In an era in which open discrimination against minorities is a thing of the past, they do not justify affirmative action as a counterbalance to racism, but instead to promote "diversity".
Their formidable CVs guaranteed their study generous coverage in the US media. The New York Times opined that the book "will most likely lead the charge in a liberal counter-offensive to recast the debate over affirmative action".
Ward Connerly, the black University of California regent and one of affirmative action's most effective foes, conceded in an interview that he was "impressed by the research". But he vehemently disagreed with the book's conclusions because "no mountain of data and statistics can justify discrimination" by race.
Mr Bok and Mr Bowen said they had set out to fill a gap in the affirmative action debate, where there was very little hard information amid the heated rhetoric and ideological argument.
The book is the result of a three-year study by Mr Bok, a political scientist, and Mr Bowen, an economist. It was sponsored by the Andrew Mellon Foundation, which Bowen heads.
It draws on a database built up by the Mellon Foundation on 45,000 people who entered 28 private and public colleges in 1976 and 1989, and who responded to survey questions on their college progress and careers.
Mr Bok and Mr Bowen claimed that their findings had debunked the conservative "mismatch hypothesis" that minorities admitted to leading universities found themselves "intimidated, outmatched and overwhelmed" and might have fared better in less challenging institutions.
Of black students with SAT scores of less than 1,000 who attended the top eight colleges in the sample, 88 per cent graduated. At the six least-selective institutions, by contrast, only 65 per cent graduated.
Blacks graduating from the elite colleges earned 70 to 85 per cent more a year, with those who entered university in 1976 now earning an average of about $70,000. About 40 per cent went on to complete doctoral or professional degrees, compared with 37 per cent for white students.
According to the authors, these figures spike the argument that students supposedly promoted beyond their abilities are actually worse off.
Perhaps more disturbing to Republicans, the study demonstrates how strongly students themselves believe in affirmative action. Forty-two per cent of white students said they should be strengthened, 36 per cent that they should be retained. Only 21 per cent wanted them weakened.
These figures held even for white students who had not got their first-place choices at university, apparently contradicting the claim that these policies create racial resentment. "It is another myth laid to rest," Mr Bok said. The study, however, did not pull punches on the downside. The grade point average of black students at the colleges was 2.61 on a 4.0 scale, compared with 3.15 for white; this difference of 0.52 was "very large".
A chart showed that white students with a SAT score of 1,250 to 1,299 had a 74 per cent chance of admission to five top colleges; for a black student with the same grades it was only 23 per cent.
Roger Clegg, of the conservative Center for Equal Opportunity in Washington, said: "The fact remains that it makes a great difference whether you are white or black."