This paper reports estimates of models of the determinants of quality in day care centers. The analysis examines the sensitivity of the results to specification issues that have not been investigated previously. In the best-fitting models that survive an extensive set of specification tests, group size and child-staff ratio have small impacts on the quality of care provided. The effects of staff education and training are typically small as well. The results raise questions about the knowledge base on which to make policy recommendations concerning the benefits of regulations and subsidies intended to improve the quality of child care.

David M. Blau is a professor in the Deportment of Economics and the Carolina Population Center at the University of North Carolina at Chapel Hill, and is a coeditor of the Journal of Human Resources. He is grateful to Deborah Phillips for generously making available the data for this paper, and to Dongchun Wang for capable research assistance. Financial support was provided by a grant from the National Institute of Child Health and Human Development. The author has benefited from the helpful comments and suggestions of Carol Rapaport, Robert Hauser, Deborah Phillips, seminar participants at Penn State University and the University of Wisconsin, and two referees. The author claims sole responsibility for opinions and errors. The data used in this article can be obtained beginning August 1997 through July 2000 from the author at Gardner Hall, University of North Carolina, Chapel Hill, NC 27599-3305.