In 1980 the National Center for Education Statistics (NCES) of the U.S. Department of Education sponsored a large-scale study of high school seniors and sophomores throughout the United States, including students in various types of private schools. Although the study did not include a large number of private school students, as they are not a large percentage of American high school students, the inclusion of these students made possible the examination of two questions related to private schools. One question is how much the private sector contributes to social divisiveness or segregation: segregation of the rich from the poor, segregation among religious groups (since most private-sector schools are organized by a religious group), and segregation of blacks, Hispanics, and whites. A second question was the relative effects of the public and private sectors on achievement in basic skills, as measured by standardized tests in vocabulary, reading comprehension, and mathematics administered to sophomores and seniors.
These questions were particularly relevant in the context of policy questions raised with increasing frequency in the preceding decade. Some of these questions concerned potential policies that would have the effect of restricting enrollment in private schools (the possibility of using racial balance as a criterion for a private school's continued tax exemption), but most concerned policies that would have the effect of increasing private school enrollment. The two most important of these were the possible use of educational vouchers at the state level and the possible introduction of federal income tax credit for a portion of tuition paid by parents of the children attending private schools.
The authors (with Sally Kilgore) carried out a detailed examination of these two questions, first in a report to NCES in April 1981 (Coleman, Hoffer, and Kilgore 1981) and second in a book published in 1982 (Coleman, Hoffer, and Kilgore 1982a). The results were generally more favorable to the private sector than to the public sector on both counts, with some exceptions and some caveats. A major caveat was that the sample of non-Catholic private schools was insufficiently large (and possibly biased because of nonresponse) that any generalizations involving non-Catholic private schools could be made only tentatively. An