“After adjusting for selected student characteristics,
the difference in means was near zero and
not significant. In the second set of analyses, Catholic
schools and Lutheran schools were each compared to
all public schools. The results, both with and without
adjustments, were similar to the corresponding results
for all private schools.”
………
Math, 4th grade level:
“After adjusting
for selected student characteristics, the difference in
means was -4.5 and significantly different from zero.
(Note that a negative difference implies that the average
school mean was higher for public schools.) In the
second set, Catholic schools and Lutheran schools were
each compared to all public schools. The results, both
with and without adjustments, were similar to the corresponding
results for all private schools.”
……….
Reading, 8th grade level:
“After adjusting for selected
student characteristics, the difference in means was
7.3 points and significantly different from zero. In
COMPARING PRIVATE SCHOOLS AND PUBLIC SCHOOLS USING HIERARCHICAL LINEAR MODELING iii
the second set, Catholic, Lutheran, and Conservative
Christian schools were each compared to all public
schools. The results, both with and without adjustments,
were generally similar to the corresponding
results for all private schools. The only exception was
that the average difference in adjusted school mean
scores between Conservative Christian schools and all
public schools was not significantly different from zero.”
…………..
Math, 8th grade level:
“After adjusting for selected student characteristics, the difference
in means was nearly zero and not significant. In
the second set, Catholic, Lutheran, and Conservative
Christian schools were each compared to all public
schools. While the results for Catholic schools, both
with and without adjustments, were very similar to the
corresponding results for all private schools, the results
for the other two types differed.”
………..
“Summary
In grades 4 and 8 for both reading and mathematics,
students in private schools achieved at higher levels
than students in public schools. The average difference
in school means ranged from almost 8 points for grade 4
mathematics, to about 18 points for grade 8 reading.
The average differences were all statistically significant.
Adjusting the comparisons for student characteristics
resulted in reductions in all four average differences
of approximately 11 to 14 points. Based on adjusted
school means, the average for public schools was significantly
higher than the average for private schools
for grade 4 mathematics, while the average for private
schools was significantly higher than the average for
public schools for grade 8 reading. The average differences
in adjusted school means for both grade 4 reading
and grade 8 mathematics were not significantly different
from zero.”
“Policymakers, parents, and other interested citizens often assume that private schools,
on the whole, are better academically than public schools. But is this empirical
assumption actually supported by evidence?
For the most part it is not, suggests the study of urban public and private high school students
described in this paper.”
“…To test various assumptions made in this study, another researcher, Dong Wook Jeong, performed
a series of sensitivity and replication analyses using the same group of students.
These analyses included reorganizing the data quasi-experimentally using propensity score
analysis (a statistical technique that estimates the effects of an educational “treatment” on a
group of students when the treatment was not actually done). They also included testing the
data for clustering (looking at whether the data converge around certain variables) and introducing
other non-school controls, such as the influence of peers on student achievement.
All of these analyses produced the same results as Wenglinsky’s initial analysis—namely, that
the private school effects, in most instances, could be explained by the demographics and
family characteristics of the students.”
There are a number of studies that compare public vs. private schools, and while private schools do indeed appear to outperform at first glance, once student variables are taken into consideration, those differences largely disappear.
You can review studies comparing private and public, and private/public charters vs. traditional public schools, etc., and you will see that public schools tend to do better or perform at similar levels, on average, vs. private schools once student variables have been accounted for.
While proponents of privatization like to claim that private schools do it for less money, at least around here, private schools cost a lot more per pupil than public schools do.
