Over the last generation, the instructional staffing system in American higher education has experienced a significant reduction in the proportion of jobs for full-time tenured and tenure-track faculty members and a dramatic growth in fixed-term full- and part-time instructional jobs without tenure. About 70 percent of the people teaching in college today hold these temporary jobs and are known as "contingent" faculty and instructors. Particularly in the case of part-time/adjunct faculty members, contingent instructors receive disproportionately low pay and inadequate employment benefits such as pensions and health insurance. This report extends previous research on these trends. Specifically, it describes how public colleges and universities employ and compensate both full- and part-time faculty members to staff undergraduate courses. It provides a national overview of who is teaching which courses, and at what salary, in public colleges and universities. The results document the system-wide switch to contingent instruction and the disproportionately low salaries associated with part-time instructional employment. The report concludes with a strategy--a new interactive model to allow institutional and state policy makers to calculate the costs of increasing the ratio of full-time tenured and tenure-track faculty members in the classroom, and of moving toward pay equity for contingent faculty members. Institutions and states can use this model to develop an incremental financial plan to achieve a more stable and equitable staffing structure for their colleges and universities. (Contains 8 charts, 6 tables, and 5 endnotes.) [This report was prepared by JBL Associates, Inc. at the request of the higher education department of the American Federation of Teachers.]