The actual record of births in the last fifteen years clearly indicates that the size of annual graduating classes from secondary schools will begin to decline by the end of this decade. Such a trend will be a significant environmental characteristic for the higher educational community, inasmuch as graduates from secondary schools comprise the principal source of demand for higher education. Because of the variations among geographical subdivisions in birth rates, migration, and anomalies in the grade-by-grade enrollment, the patterns of change for small geographical regions may be expected to vary from those on a state or nationwide basis. For the application under investigation, the number of graduates from public and private secondary schools in each of the sixty-seven counties in Pennsylvania were projected over a 10-year period by application of what is characteristically referred to as the cohort-survival method. Using enrollment data collected routinely by the Pennsylvania Department of Education, cohort-survival rates were computed for a number of historical years between each pair of grade-levels between one and graduation for primary and secondary school enrollments of each county. These rates were then applied to the most recently available compilations of grade-by-grade enrollment to generate projections of high school graduates for each county over the specified time horizon. (Author)