Wightman's research found that adding a preference based on socioeconomic factors to the UGPA/LSAT criteria would not significantly increase the number of African-Americans, because among applicants with similar socioeconomic backgrounds, those self-identified as "white" significantly outperformed African-Americans on the LSAT. Wightman, supra note 96, at 45. Wightman's study also showed that the mean LSAT score for black students was consistently seven to eight points lower than white students of the same socioeconomic class for each of the four socioeconomic classifications (upper, upper-middle, middle, lowermiddle). See id. at 42. Indeed, the group of black law students classified as upper class-both parents had graduate or professional training and held professional jobs-had a mean LSAT score about six points lower than white law students in the lowest classification, lower-middle-neither parent was college educated and both were engaged in blue collar work. See id. at 41-42. Wightman's findings have been further corroborated by a recent empirical study by a researcher at Testing for the Public, a nonprofit educational corporation that helps students prepare for graduate school admission examinations. William C. Kidder, Does the LSAT Mirror or Magnify Racial and Ethnic Differences in Educational Attainment? A Study of Equally Achieving "Elite" College Students, 89 CAL. L. Rav. 1055 (2001). Kidder's study used a database of 1996, 1997, and 1998 applicants to Boalt Hall from fifteen highly selective colleges and universities. Id. at 1058. For each undergraduate institution, he matched the LSAT score of each African-American, Latino, Native American, and Asian Pacific applicant with the average LSAT scores of white applicants who had comparable UGPAs. Id. at 1073. Thus, the LSAT score of a minority applicant from UCLA with a UGPA of 3.4 would be compared with the average LSAT score of all white applicants from UCLA with UGPAs ranging from 3.3 to 3.5. Id. Kidder then calculated the average gap in LSAT score between, for example, all Latino applicants (from all fifteen undergraduate institutions) and white applicants from the same institution with comparable UGPAs. Id. His results showed that the 247 African-American applicants had an average LSAT gap of 9.2 as compared to white applicants with comparable grades at the same college or university. Id. at 1074. The LSAT gap for the 407 Latino applicants was 6.8; for the 33 Native American applicants, 4.0; and for the 1043 Asian Pacific applicants, 2.5. Id. Because the Boalt Hall application database further distinguished among various Asian Pacific nationalities, Kidder was able to determine that some Asian applicant groups had higher LSAT gap scores than the overall average Asian gap: Filipinos, 5.5 and Vietnamese/Thai/Cambodian/Laotian, 5.3. Id. at 1075. Kidder also did a second, even more precise study matching each African-American, Latino, and Asian Pacific applicant with white applicants who had comparable UGPAs and were also taking the same major. Id. at 1079. For example, a Latino applicant from UCLA majoring in political science would be compared only to white political science majors from UCLA with comparable grades. Id. The LSAT gaps did not change appreciably. Id.