This study investigates how local school districts behave in allocating their budgets among teachers, other professional educators, support personnel, and nonpersonnel inputs. Demands for school inputs are estimated using U.S. Office of Education data on the expenditure and staffing patterns of large (enrollments in excess of 10,000 students) school districts in the 1969-70 school year. In general, results suggest that districts' allocative behavior at the margin is quite different from their average allocative behavior. In particular, relatively small proportions of budget increases (occasioned, perhaps, by reforms in school finance) would be allocated to employing additional teachers. (Author)