Contemporary educational thought holds that one of the pivotal causes of inadequate school performance is the inability of schools to adequately staff classrooms with qualified teachers, especially in fields such as math and science. Shortages of teachers, it is commonly believed, are at the root of these staffing problems and are, in turn, primarily due to recent increases in teacher retirements and student enrollments. This session will reexamine this view by analyzing nationally representative data on the demand, supply, and turnover of teachers, with particular focus on comparisons between math, science, and social studies teachers.