Cost-effectiveness analysis provides a useful tool for choosing between alternative desegregation plans or justifying one particular plan. Previous analyses of school desegregation effects on white enrollment, which focus only upon costs, have had limited use for policy. Traditional cost-benefit analysis poses problems because of the difficulty of attaching monetary values to policy alternatives and because the courts consider school desegregation a a goal in itself rather than just one of many alternatives leading to other goals. In cost-effectiveness analysis, the school desegregation goal may be identified as interracial exposure, and the analysis can proceed using (1) a measure of the extent of interracial exposure indicating the proportion of white students in the average black child's school; and (2) information on school racial composition after projected reassignments and after white flight. Analysis of proposals for the San Diego (California) Independent School District using this method indicated that the American Civil Liberties Union plan would maximize interracial exposure more than either the school district plan or the condition of no further desegregation. By varying the white flight values in analysis, as was done for the Port Arthur (Texas) Independent School District, the effects of white flight on the value of desegregation plans can be estimated. (Author/MJL)