THE NOTED SOCIOLOGIST and legal scholar Richard Lempert has warned, “Nothing is so helpful as good empirical research and nothing can be so bad as poor research that becomes influential.” Richard Sander (a UCLA law professor) and Stuart Taylor Jr. (a journalist/lawyer) describe their book Mismatch as “mostly an empirical book.” It should be evaluated as such. Sander and Taylor expend considerable effort to make Mismatch influential, with the book’s release timed the day before the US Supreme Court heard arguments in the affirmative action case Fisher v. University of Texas at Austin and countless op-eds and so on. The attention is more than unfortunate, for the book is highly misleading.

Sander and Taylor’s “mismatch” hypothesis asserts that affirmative action harms its beneficiaries by placing them in settings where they cannot compete academically and so learn less and perform less well than they would in less selective institutions. This thesis has been advanced over the years by a number of affirmative action critics, but none of these earlier efforts were as ambitious as Mismatch in attempting to claim the mantle of social science evidence.

Affirmative action in American law schools is a major theme in Mismatch, and Sander’s 2004 article “Systemic Analysis,” a study of black law students published without peer review in a student-edited journal, is the fountainhead for much of what Sander and Taylor say. Even after eight years and voluminous, empirically based criticism, Sander (with Taylor) sticks to his guns in Mismatch: 

[A]ll the factual claims and the data presented in “Systemic Analysis” withstood all scrutiny. All of its tables, models, and analyses were replicated. […] [T]he debate (such as it was) concerned only the inferences I drew from the facts and models I presented.

To borrow from Mark Twain, there is evidence here of a “high talent for inaccurate observation.” Sander and Taylor use the concepts of “replicated” and “withstood all scrutiny” in ways that strain credibility and depart from social science norms. To give but one example, in “Systemic Analysis” Sander used Linda Wightman’s 2001 data to argue that ending affirmative action would only decrease African-American enrollment in law school by 14 percent, and this forms the basis for his climactic conclusion that ending affirmative action would actually increase the number of African Americans who become lawyers. But many scholars (including Wightman) have been careful to point out that this “grid model” paints an unrealistically rosy picture, because it is untethered to the schools where candidates actually apply (a logistic regression model taking this into account projected a 38 percent national decline). In fact, when my co-authors and I looked closely at Sander’s table, it was evident that he violated the very grid model methodology he espoused by deleting all students with the very lowest credentials, effectively puffing up his post–affirmative action performance estimates. Other scholars reject Sander’s blending of 2001 admissions data with bar passage data from students entering law school in 1991. Sander and Taylor repeat this flawed set of claims in their book.

Replication concerns in Mismatch a...