In recent years, increases in public school enrollment and possibility that teacher shortages exist or will exist in specific geographic regions and subject areas have raised questions about the supply of and demand for public school teachers. Information submitted by Local Education Agencies (LEAs) in Pennsylvania and certification records were examined to determine the supply of and the demand for teachers by Pennsylvania public schools and to determine if the state is experiencing a teacher shortage. Analysis of this data yielded the following results and conclusions: (1) in general, a more than adequate supply of certified teachers exists to meet the demand for classroom teachers; (2) although there was a demand for elementary teachers to fill new positions generated by increasing enrollments and teachers leaving their positions, there was little or no demand for secondary teachers to fill new positions; (3) because only minor differences existed in the demand for teachers by certification area, it appears that special incentive programs to influence prospective teachers to enter special areas are unnecessary; (4) hiring patterns related to newly certified teachers suggest that there was a significant surplus of available teachers; and (5) overall study results appear to indicate that there is no unmet demand for classroom teachers based on data for 1989-1990 and 1990-1991. (IAH)