Studies of the process of modernization in Africa focus attention upon the primacy of the occupational structure rather than the educational system in the determination of rates of social mobility. Where occupational placement depends on educational qualifications, however, the educational system is a crucial channel of social mobility. Ghanaian data on patterns of social selection into institutions of higher education suggest that, despite the expansion of the number of school and university places, there are bottlenecks in the educational system that ensure the placement of children of the elite in high occupational positions. These processes represent a closure of the elite giving rise to differential opportunities for various social groups within the modern sector of the economy akin to those associated with the class divisions of industrial societies.