Many supporters of using racial preferences in university admissions have distorted debate about the practice by fostering some misleading myths as to how it actually works. As the Supreme Court prepares a climactic decision, to be issued by early July, on the preferential admissions systems at the University of Michigan’s undergraduate and law schools, let’s examine some of these myths and the realities they have obscured. And let’s consider the likely effect on diversity if colleges were to give preferences based on disadvantaged socioeconomic status instead of race.

The most Orwellian myth appeared on the signs held by many of the demonstrators thronging the Court’s plaza during the April 1 arguments in the Michigan cases. They equated a ruling against preferences with a return to state-sponsored discrimination against African-Americans. The real issue, of course, is whether to continue state-sponsored discrimination in favor of black and Hispanic applicants, and against Asian-Americans and whites.

Some other myths have gained enough currency even among less-partisan observers to deserve more detailed rebuttal:

Myth. Banning racial preferences would "resegregate" top universities.

Reality. This would be extremely disturbing if true. But it is not. That is the lesson of both recent experience and an important new study by the Century Foundation. It found that replacing racial preferences with "economic affirmative action" for disadvantaged students would produce a dramatic increase in economic diversity and only a modest decline in racial diversity, with black and Hispanic students dropping from 12 percent of the students at 146 top universities to 10 percent.

The "resegregation" alarums assume that without racial preferences, colleges would consider only grades and test scores. But colleges have never done that and never will. Since racial preferences by state universities were banned in California, Texas, and Florida during the late 1990s, those universities have found other ways to admit roughly as many black and Hispanic students as before. (The exceptions are the two most elite California campuses, Berkeley and UCLA, where black numbers have dropped by about one-half and one-fourth respectively.)

These states have all chosen to admit the top students from even the worst high schools in the poorest neighborhoods based on class rank alone. This is a crude approximation of economic affirmative action. But the Century Foundation study, released on March 31, suggests that giving economic preferences to the best-qualified disadvantaged students on an individualized basis would work much better. Many elite colleges around the country already purport to do this, but make only token efforts.

The study, written by Anthony P. Carnevale of the Educational Testing Service and Stephen J. Rose, a research economist, advocates retaining racial preferences, too. But it refutes scholarly conventional wisdom that economic preferences would add little or no racial diversity. And another Century Foundation expert, Richard D. Kahlenberg, uses the same data to advocate substituting economic for racial preferences. This "would produce almost as much racial diversity as using race [and] far more economic diversity," he writes, while alleviating "the under-representation of students from poor and working-class families at elite universities, [which] is far greater than the underrepresentation of students of color."

Myth. Racial preferences are needed to help downtrodden descendants of slaves overcome white privilege.

Reality. This wraps together several sub-myths and half-truths:

• Most recipients of racial preferences are not downtrodden. William Bowen and Derek Bok noted in 1998, in their pro-affirmative-action book The Shape of the River, that 86 percent of blacks at the 28 selective universities they studied were middle or upper middle class. Economic affirmative action, stresses Kahlenberg, "would benefit a quite different group of African-Americans and Latinos, high achievers who overcame economic deprivation-as well as a whole new cohort of working-class whites and Asians."

• Racial preferences do virtually nothing for the vast majority of black people, including the some 45 percent who drop out of high school and the many graduates of inner-city schools who are so unprepared for serious academic work that no elite college would admit them.

• Most white and Asian applicants rejected on account of preferences are not privileged. Indeed, the Century Foundation data suggest, they may well be less affluent on average than the black and Hispanic students who receive racial preferences.

• Most of the students who lose out because of racial preferences are not white; they are Asian-American, The New York Times suggested in a February 2 article, based largely on surging admissions of Asians and largely flat admissions of whites since racial preferences were banned in California and Texas.

• More and more preferences go to descendants not of slaves but of Hispanic immigrants.

• While whites benefit disproportionately from preferences for children of rich donors and alumni, the most logical offset would be economic-not racial-preferences. And colleges are free to end their preferences for the privileged.

Myth. The SAT and other standardized tests are culturally biased.

Reality. It’s true that there are large racial disparities in average SAT scores-1070 for Asians, 1060 for whites, 910 for Hispanics, and 857 for blacks among seniors in 2002, according to the College Board. But if these scores understated blacks’ academic potential, then blacks would do better in college than whites and Asians with similar scores. The opposite is the case: Black and Hispanic students "have college grade-point averages that are significantly lower than those of whites and Asians" with similar scores, according to a 1999 College Board report.

Myth. Racial preferences do not lower academic standards.

Reality. Most preferentially admitted students are in the bottom fourth of their classes academically, studies suggest. Indeed, in a brief supporting racial preferences in law school admissions, the Law School Admission Council stressed that "only about 25" black students do well enough in college each year to rank among the more than 4,000 applicants to the most selective law schools with grades and LSAT scores high enough to qualify under the standards applied to most white and Asian applicants.

Myth. Preferences are temporary, because racial gaps in academic performance are narrowing.

Reality. In fact, the black-white SAT gap, which had declined substantially until about 1988, has grown since then from 189 to 203 points, according to a March 5 article in The Journal of Blacks in Higher Education. It added that "there is no compelling evidence that any improvement is in the offing."

Myth. Racial preferences are a great thing for black and Hispanic students.

Reality. It’s true that elite-college credentials are a valuable asset. But the very best black and Hispanic students suffer greatly from the inaccurate but widespread perception that they must have needed preferences to get in. And some students who did win admission through racial preferences might be better off at the top of their classes at less-elite colleges. "Affirmative action is contributing to the number of minority students getting lower grades, which seems to contribute to them selecting non-high-achievement careers," researcher Stephen Cole, principal author of a recent book titled Increasing Faculty Diversity, told The Chronicle of Higher Education.

Myth. Racial gaps in academic performance are the fault of inferior schools and poverty.

Reality. These are clearly a big part of the reason. But other factors are also at work. "Whites from families with incomes of less than $10,000 had a mean SAT score that was 46 points higher than blacks whose families had incomes of between $80,000 and $100,000," according to The Journal of Blacks in Higher Education. In his new book, scholar John Ogbu documents "a wide gap in academic performance … between white and black students" from similar socioeconomic backgrounds at the same schools in affluent Shaker Heights, Ohio. In Black Students in an Affluent Suburb: A Study of Academic Disengagement, Ogbu attributes such gaps largely to "the ways minorities interpret and respond to schooling," including "cultural and language differences."

Writer John H. McWhorter puts part of the blame on affirmative action itself, because it teaches black and Hispanic students that they need not meet the same standards as whites and Asians. "In this light," he writes, "the maintenance of affirmative action hinders the completion of the very task it was designed to accomplish, because it deprives black students of a basic incentive to reach for that highest bar."