Richard Sander of the University of California at Los Angeles School of Law asserts that affirmative action in law schools hurts black law students because it puts them in schools where their credentials are below the median; consequently, they cannot academically compete. Sander claims to have empirically proven this “mismatch thesis,” but his findings have been contested. Some researchers have documented a “reverse mismatch effect”: Black law students attending higher-status schools do better, not worse, in terms of bar passage rates compared to counterparts attending lower-prestige schools. (This is true of all law students � higher expectations tend to improve student learning.) Others challenge Sander’s findings because he does not pose a hypothesis and determine whether the evidence supports it, as social scientists do. Instead, he asserts conclusions and then scours for evidence to support his argument, as lawyers do. Because he publishes without peer review � unlike social scientists � serious questions plague his research.

Sander now says there are data � the bar exam scores of blacks and Latinos in California � that can help resolve the debate. Thus far, the bar examiners have denied his request. Sander asks: Why? Isn’t it perfectly reasonable to get more data? Before we board the train, we must ask where it’s going. Sander says the information will help because the bar scores � versus readily available bar passage rates � “are a measure of what law graduates have actually learned; this allows one to study not only how the mismatch might affect bar passage but also how it might affect actual learning.”

Not true. This is his assumption � not proven fact. What the bar exam tests and what is learned in law school are not the same. First, the bar exam is a pass/fail test. Unlike in law school, there’s no incentive to get an A. Second, the bar exam claims to determine minimum competency to practice law: It does not measure relative learning in law school. Third, bar test scores are a product of learning in bar-examination cram courses as much as actual learning in law school.

Data can’t prove Sander’s case

Admitted to the bar are some people who never attended law school, but took and passed the bar exam. Some highly regarded legal scholars � those who teach law � have never taken the California bar exam; others initially did not pass. In fact, elite law schools (those with the highest passage rates) devote little effort to teaching what is tested on the bar exam. How then can one categorically say bar exam score differentials reflect actual learning in law school? Shouldn’t this hypothesis first be tested and demonstrated?

Sander’s repeated efforts to secure National Science Foundation funding for his project failed largely for this reason. According to outside experts assigned to assess the project, the mismatch hypothesis that affirmative action academically harms black law students cannot reasonably be tested by analyzing the bar scores of black and Latino test takers. It’s too big a leap from the data he wants to the conclusion he has reached.

There are also privacy concerns. The bar examiners turned down Sander because test takers provide racial and gender information on the understanding it will be used to determine whether the exam is fair, not for other purposes � like confirming the mismatch theory. Moreover, because so few black students matriculated in a given class at some schools, student identity could be discerned.

In fact, higher black failure rates on the bar exam are connected to testing differences being researched throughout the educational pipeline. (Think about the debate over testing mandated by No Child Left Behind.) Differences obtain among whites and Asians on the SAT (where some groups of Asians outscore whites in math) as well as among blacks and whites. Are these standardized test score differences related to classroom learning? While Sander has reached his conclusion, social science recognizes this as a question yet to be definitively resolved.

Fine. But if the mismatch hypothesis doesn’t explain the racial gap in exam performance, what does? One possibility is stereotype threat � the fear that one’s performance will confirm prevailing negative stereotypes about one’s social group � which has been well documented as a factor depressing academic performance. Sander’s Sept. 26 Los Angeles Times commentary invites us to “imagine.” So consider this: Imagine that you are a law student whose social group is considered academically substandard and that the group’s asserted inadequacies are continually discussed in the national press, among members of the faculty who teach you and among your classmates. What effect might this have on your academic performance? Imagine indeed.

Cheryl I. Harris is a professor at the University of California at Los Angeles School of Law. Walter R. Allen is the Allan Murray Cartter Professor of Higher Education and Sociology at UCLA.