"According to the article, "Study: HBCU Graduates Earn Less Than Black Graduates of Traditionally White Institutions" (see Diverse, May 17), the economic gains of Blacks who attended historically Black institutions as opposed to Blacks who attended traditionally White institutions declined dramatically from the 1970s to the 1990s, according to "The Causes and Consequences of Attending Historically Black Colleges and Universities," by Drs. Roland G. Fryer and Michael Greenstone. After considering and dismissing other plausible explanations, Fryer, an assistant professor of economics at Harvard University, attributed the "decline" to the enhancements that White institutions have made in educating Black students."