Data for this report are taken from the 1987-88 Schools and Staffing Survey (SASS), which was designed to measure teacher supply and demand conditions, characteristics of the teacher workforce, and factors related to teacher supply and demand. This analysis used a subsample of the SASS teacher sample consisting of 2,041 newly hired public school teachers and 954 newly hired private school teachers. In the 1987-88 school year, 152,000 teachers were newly hired, 112,000 in public and 40,000 in private schools. Only 27 percent of public and 19 percent of private school teachers were supplied by the pool of "newly minted" college graduates who have traditionally met the nation's demand for new teachers. The primary source for new hires was the reserve pool of former teachers. Reentrants supplied 41 percent of new hires for public schools and 44 percent in private schools. Transfers from other teaching positions supplied 19 percent of public and 23 percent of private new hires. A fourth source of new hires was the delayed entrant, first-year teachers who engaged in other activities after completing their degrees but before entering teaching. Measures of teacher qualifications are needed to distinguish better among teachers of varying quality. Continued reporting of these data will be useful in tracking the relative contribution of each supply source in meeting the demand for newly hired teachers. Ten tables and five figures present survey findings. Technical notes on survey methodology are included, and an appendix contains 10 tables of standard errors. (SLD)