Empirical evaluation of the effect of school quality, or type and amount of resources per student, on adult earnings requires a conceptual framework. A model of the returns to schooling in a simple human capital growth context is extended to illustrate how factors such as consumption benefits of students, parental concern over equity between siblings, and use of schools to facilitate parental labor supply can alter the apparent return to school quality. The need for microlevel time diary and other data on human capital formation in both classrooms and families is highlighted. Copyright 1996 by MIT Press.