Researchers and faculty groups have become increasingly concerned with the changing mix of tenure-track and non-tenure-track faculty appointments (American Association of University Professors, 2001, 2003; Baldwin & Chronister, 2001; Benjamin, 1998a, 1998b, 2002; Chait, 2002). Between 1975 and 1995, the number of part-time faculty increased by 103%, and the number of full-time tenure-ineligible faculty by 93%. Meanwhile, the number of probationary, tenure-track faculty decreased by 12%. The most recent estimates suggest that more than half of all instructional staff are contingent faculty—working in part-time or in full-time, but tenure-ineligible, positions (American Association of University Professors, 2001; Baldwin & Chronister, 2002; Gappa, 2001; US Department of Education, 2000). Why has higher education become so reliant on contingent workers? Critics are quick to point to problems with the tenure system. They suggest that tenure increases costs, stifles faculty productivity, and decreases the ability of colleges and universities to adapt in a rapidly changing society (Baldwin & Chronister, 2001, 2002; Gappa, 2001; Leslie, 1998; Massy & Wilger, 1992; Tierney, 1998). Others argue that an aging faculty and a surplus of aspiring