For a number of years American colleges and universities have increasingly relied on adjunct professors. As full professors retire, they're often replaced with part timers - who typically earn less, receive no benefits and have little say in academic affairs. Today part-time instructors account for about half of all faculty at the nation's public and private higher education institutions. Administrators defend the trend as a necessary cost-cutting measure amid rising expenses and reduced revenues. But many adjuncts have begun to fight for better pay and benefits. Guest host Susan Page and a panel of experts talk about the growing reliance on adjunct professors.