School choice is advocated on the theory that deregulation and greater market control can restructure and improve education. While certain market strategies of improvement are worth exploring, complex production functions, unclear goals, and the political role of education in society limit the extent to which education can be understood and improved as a market. This document clarifies the public choice critique of education, describes the conditions of choice in a large urban magnet-based voluntary desegregation program, and analyzes central assumptions and propositions of public choice theory about family preferences and the organizational effects of choice. Data from the Milwaukee (Wisconsin) Public Schools (MPS) magnet/voluntary desegregation program were collected and analyzed. The following major topics are discussed: (1) the political and economic arguments supporting choice in public education; (2) differences and similarities between the MPS system and traditional systems, emphasizing limitations on mandatory assignment policies; (3) choices and attendance patterns of inner city black families and the correlates of magnet participation; (4) the effects of choice on teacher attitudes and organizational outcomes as measured by a teacher survey; and (5) potential system-level consequences of choice in MPS for achieving goals of educational equity and efficiency. Statistical data are included on 20 tables and 10 graphs. The following materials are appended: (1) a 255-item bibliography; (2) the results of a teacher survey of elementary and middle magnet and nonmagnet schools; (3) the differences in resource inputs between magnet and nonmagnet schools; and (4) a scatterplot of student composition variables for elementary magnet and nonmagnet schools. (FMW)