This paper presents findings of research that examined the effects of two recent educational reforms--restructuring to produce effective schools and mainstreaming students with disabilities into general classes. Specifically, the relationship between general- and special-education achievement to school-environment quality indicators in 56 southern California schools was explored. Applying a theory of instructional tolerance that focuses on a microeconomic model of resource allocation, it was predicted that the school-level joint outcomes of general- and special-education achievement would diverge and relate differentially to indicators associated with greater school effectiveness. Data were obtained through a survey of 1,943 elementary teachers and 923 junior high teachers, an analysis of Basic Academic Skills Samples (BASS) test scores of special-education students, and an analysis of general-education students' California Assessment Program (CAP) scores. Results suggest that effective-schools research failed to produce unambiguous quality indicators nor descriptions of new technology. The data showed inverse relationships between changes in general- and special-education students' achievement in the sample schools, and inconsistent and differential relationships between school-environment quality indicators and the achievement change of the two groups of students. Additional resources and/or new instructional technologies are needed if general- and special-needs students are to be merged. Two figures and five tables are included. Contains 71 references. (LMI)