In the 1960s teacher demand and supply increased rapidly to match the increasing school enrollments of those years in Pennsylvania. But due to declining enrollments and lower than normal teacher replacement needs in the 1970s the demand for teachers began to fall faster than the supply. Rather conservative projections indicate that teacher supply may well average 50 percent higher than demand in the mid-1980s. However, this oversupply is mitigated by bachelor's graduates in education consistently ranking among the top 10 of the 23 major disciplines for those with some kind of full-time employment five months after graduation. The analysis is based on extensive data relative to: population change, public school enrollment, public and nonpublic schools, and grade and age level characteristics as they relate to teacher demand; sources of teacher supply, teacher graduates, out of state teacher supply, and supply reservoirs; and the relationship of teacher demand to supply in Pennsylvania. (Author/DS)