This presentation by James S. Coleman examines several questions: Does desegregation bring about loss of whites from schools in a desegregated system? If so, what is the extent of that loss? And what are the conditions, in the demography and ecology of the system, as well as in the form of the desegregation policy, which affect the extent of that loss? A segregation index was constructed to aid in answering these questions. The change in the number of white students in a system during a school year was analyzed as a function of change in the segregation index. Other variables were also analyzed. The examination was carried out for all school systems during the period 1968-1973. Detailed examination was given to the 21 largest central city systems. Results show that desegregation brings about an extensive loss of whites, but this loss differs radically under different conditions. Data were analyzed for 1974 and 1975 for nine cities, among the largest 21, which in a single year at least partially desegregated. The results indicate that the desegregation loss did diminsh after the first desegregation year, but it did not vanish. (Author/JM)