More than 5 million students, about 10 percent of the school-age population, are enrolled in private schools in the United States (Digest of Education Statistics, 2002). In the 1999-2000 school year, 48.6 percent of those students attended Roman Catholic schools, 35.7 percent attended schools based on other religious beliefs, and 15.7 percent attended nonsectarian private schools (Private School Universe Survey, 2001).
On average, private school students come from families with higher incomes than those of public school families, and have parents who have reached a higher level of education than the average parent (Moe, 2000). Forty-seven percent of private school students come from families making at least $75,000 a year (U.S. Census Bureau, 2002). Parents of private school students are also more likely to be white, Catholic, and Republican (Moe, 2000).
The main reason for the income difference in private school families is tuition costs. In the 1999-2000 school year, the average private school tuition was $4,689 a year. Catholic schools tend to have the lowest tuition of private schools, with an average of $3,236 that year. For other religious schools, the average tuition was $4,063, and for nonsectarian schools, which are the most expensive private schools, average tuition was more than $10,000 a year (Digest of Education Statistics, 2002).
A larger, and possibly more diverse, group of parents would be likely to send their children to private school if not for the high costs. According to the most recent Gallup Poll on the public’s attitude toward public schools, 59 percent of public school parents would send their children to private schools if given vouchers covering the full tuition (Rose & Gallup, 2003). Another survey found that the proportion was even higher for low-income parents, 67 percent of whom would be interested in sending their children to private schools if money were not an issue (Moe, 2000).
A contentious debate exists over whether private schools add to or take away from the American education system. Critics of private schools argue that the true motivation behind parents’ decisions to send their children to private schools is social elitism or separatism. They contend that parents are not actually following a belief that private schools perform better academically, but are instead interested in separating their children from those of other races or backgrounds, or are attracted to the status symbol of having their children in private schools (Cookson, 1994; Meier & Smith, 1995). They argue that those attitudes create an education system in the United States that is inequitable and segregated by class and race.
Proponents of private schools argue that the superior academic performance of private school students is evidence that the nation should replace the current monopoly of public schools with a competitive system of school choice. They maintain that such a system would increase school autonomy, which, in turn, would improve student performance (Chubb & Moe, 1990). They also argue that the bias inherent in the current private school system would be lessened by opening those schools up to more low-income and minority students through vouchers and other school choice programs (Moe, 2000).
A majority of public school parents believe that students who use vouchers to move to private schools will have improved academic achievement (Rose & Gallup, 2003), but there is conflicting evidence about whether private schools students actually make more academic progress than public school students. Results are not even conclusive in studies that use statistical controls to account for selection bias, the fact that students in private schools often come from more advantaged backgrounds.
On the surface, private schools seem to be better equipped to produce higher student performance. According to data from the U.S. Department of Education, private schools tend to have smaller class sizes, greater numbers of teachers reporting a high level of job satisfaction and influence over school practices, more demanding graduation requirements, and more students who move on to complete a bachelor’s degree (2002).
In a widely cited report from more than two decades ago, Coleman, Kilgore, and Hoffer (1981) conclude that Catholic schools raise student achievement by one grade level, even after accounting for differences in family background. The authors also found that the effect was even greater for poor and minority students, although the results from the study have been challenged by several further analyses of the same data.
Data from the National Assessment of Educational Progress provide some evidence that private school students have higher achievement, and show slightly higher scores for private school students. Selection bias likely plays a role in those higher scores, however, because when the data are analyzed with statistical controls for student background, the differences disappear (Shanker, 1991).
Studies from the 1988 National Educational Longitudinal Study have shown that, after correcting for selection bias, religious private schools do not lead to higher achievement overall, although researchers did find academic improvement for black and Hispanic students, especially those in large urban areas (Figlio & Stone, 1997). A study that analyzed achievement data from inner-city schools in New York City and the District of Columbia also found that poor, minority students attending Catholic schools with privately funded scholarships had greater achievement gains than their neighborhood peers assigned to public schools (Hill et al., 1990).
Several reasons make such analyses difficult to conduct and ultimately inconclusive. One reason is that even if students in the studies come from disadvantaged backgrounds and do well in private schools, it is impossible to know if their academic success is a direct result of private school practices. It could be that other factors, such as parent involvement or student motivation, are higher for students who participate in voucher programs or for those whose families scrape together enough money to pay tuition. Some students may also respond better to Catholic or other religious schooling. Another reason the studies are inconclusive is that it is hard to tell whether achievement differences between private and public school students would remain if more students were to attend private schools (Neal, 1998).
Another reason for the inconclusive research is that comparing private and public schools is not as straightforward as it may seem. Within both types of schools, there is a great deal of variation. In fact, a case study of eight public and eight private schools found that the type of communities in which schools were located explained variations across schools better than whether they were public or private. The study found that inner-city private schools were more similar to inner-city public schools than they were to suburban private schools (Rothstein et al., 1999).