title: Disentangling Disadvantage: Can We Distinguish Good Teaching from Classroom Composition?
abstract: This paper investigates the use of teacher value-added estimates to assess the distribution of effective teaching across students of varying socioeconomic disadvantage in the presence of classroom composition effects. We examine, via simulations, how accurately commonly-used teacher-value added estimators recover the rank correlation between true and estimated teacher effects and a parameter representing the distribution of effective teaching. We consider various scenarios of teacher assignment, within-teacher variability in classroom composition, importance of classroom composition effects, and presence of student unobserved heterogeneity. No single model recovers without bias estimates of the distribution parameter in all the scenarios we consider. Models that rank teacher effectiveness most accurately do not necessarily recover distribution parameter estimates with less bias. Since true teacher sorting in real data is seldom known, we recommend that analysts incorporate contextual information into their decisions about model choice and we offer some guidance on how to do so.
authors.affiliation: University of Arkansas, University of Southern California Dornsife Center for Economic and Social Research & RAND Corporation, 219-B Graduate Education building, Department of Education Reform, University of Arkansas, Fayetteville, AR 72701 ( gzamarro@uark.edu ).
authors.forename: Gema
authors.initials: G
authors.lastname: Zamarro
authors.affiliation: RAND Corporation, 4570 Fifth Avenue, Suite 600 Pittsburgh, PA 15213-2665, ( engberg@rand.org ).
authors.forename: John
authors.initials: J
authors.lastname: Engberg
authors.affiliation: University of Southern California Dornsife Center for Economic and Social Research, University of Southern California, 635 Downey Way, Los Angeles, CA 90089-3332 ( juansaav@usc.edu ).
authors.forename: Juan Esteban
authors.initials: JE
authors.lastname: Saavedra
authors.affiliation: American University, 215 Gray Hall, 4400 Massachusetts Ave., NW, Washington, DC 20016-8030 ( steele@american.edu ).
authors.forename: Jennifer
authors.initials: J
authors.lastname: Steele