Using data from the 1960-1977 period, this study provides a range of headcount enrollment projections for the Michigan higher education system to the year 2000 by type of institution and by age and sex of student under alternative sets of projection assumptions. The theoretical framework, methodology, and working model developed in this study are designed to reduce the uncertainty associated with long-run forecasts of the demand for higher education and provide a tool that will be of continuing use to the planning community. Enrollment is predicted by examining two factors. First is the complex economic and demographic phenomena that jointly determine the size and distribution of the population pool feeding higher education. Second is the network of environmental and behavioral relationships that determine participation rates in higher education. The study concludes that enrollment will peak in the late 1970's, remain essentially stable through the early 1980's, and then decline steadily until the mid-to-late 1990's. Other conclusions drawn by the study suggest that four-year institutions will fare slightly better than two-year schools and female enrollments will grow relative to males. Tables include statistical information on economic projections, enrollment patterns, structural equations, and exogenous variables. Three appendices are provided: Structural Equations and Variable Definitions; Demographic Methodology; and Household Demand for Higher Education. A bibliography is provided. (LC)