Open Borders? Closed Societies? The Ethical and Political Issues. Edited by Mark Gibney. New York: Greenwood, 1988. 211p. $39.95. - Latin American States and Political Refugees. By Keith W. Yundt. New York: Praeger, 1988. 236p. $37.95. - International Differences in the Labor Market Performance of Immigrants. By George J. Borjas. Kalamazoo, MI: Upjohn Institute for Employment Research, 1988. 106p. $15.95 cloth, $8.95 paper.