Classroom education has public good aspects. The technology is such that when one student disrupts the class, learning is reduced for all other students. A disruption model of educational production is presented. It is shown that optimal class size is larger for better-behaved students, which helps explain why it is difficult to find class size effects in the data. Additionally, the role of discipline is analyzed and applied to differences in performance of Catholic and public schools. An empirical framework is discussed where the importance of sorting students, teacher quality, and other factors can be assessed.

Economics is not only a social science, it is a genuine science. Like the physical sciences, economics uses a methodology that produces refutable implications and tests these implications using solid statistical techniques. In particular, economics stresses three factors that distinguish it from other social sciences. Economists use the construct of rational individuals who engage in maximizing behavior. Economic models adhere strictly to the importance of equilibrium as part of any theory. Finally, a focus on efficiency leads economists to ask questions that other social sciences ignore. These ingredients have allowed economics to invade intellectual territory that was previously deemed to be outside the discipline's realm.