The ‘Pupil’ Factory: Specialization and the Production of Human Capital in Schools

Starting in the 2013-2014 school year, I conducted a randomized field experiment in fortysix traditional public elementary schools in Houston, Texas designed to test the potential productivity benefits of teacher specialization in schools. Treatment schools altered their schedules to have teachers specialize in a subset of subjects in which they have demonstrated relative strength (based on value-add measures and principal observations). The average impact of encouraging schools to specialize their teachers on student achievement is -0.11 standard deviations per year on a combined index of math and reading test scores. Students enrolled in special education and those with less experienced teachers demonstrated marked negative results. I argue that the results are consistent with a model in which the benefits of specialization driven by sorting teachers into a subset of subjects based on comparative advantage is outweighed by inefficient pedagogy due to having fewer interactions with each student, though other mechanisms are possible. * I thank Terry Grier and Andrew Houlihan, for help and guidance in conducting the experiment. I am grateful to Will Dobbie, Richard Holden, Simon Jaeger, Andrei Shleifer, Jörg Spenkuch, Chad Syverson, the Editor and three anonymous referees for helpful comments and suggestions. Meghan Howard Noveck and Rucha Vankudre provided exceptional project management oversight. Tanaya Devi and Hannah Ruebeck provided particularly exceptional research assistance. Lisa Phillips, and Brecia Young provided excellent research assistance. Financial Support from Eli Broad and the Edlab’s Advisory Group is gratefully acknowledged. Correspondence can be addressed to the author by email at [email protected]. The usual caveat applies.