Vouchers Hike Black Student Test Scores

Published June 1, 2002

Compared to their counterparts who remained in public schools, low-income African-American students achieved impressive test score gains when they used privately funded school vouchers from the School Choice Scholarships Foundation (SCSF) to attend private schools in New York City, according to researchers from Harvard University, Mathematica Policy Research, Inc. (MPR), and the University of Wisconsin.

Parental satisfaction also was higher among parents of students who attended a school of choice.


  • Standardized reading and math test scores for African-American students who had used the vouchers to attend private schools for three years were 9.2 percentile points higher than those of comparable African-American students who did not attend a private school;
  • Overall test scores for African-American voucher recipients who attended a private school for at least one of the three years were, on average, 7.6 percentile points higher than those of African-American students who had never attended a private school;
  • When asked to assign a grade to their children’s school, 42 percent of voucher parents gave their school an “A,” while only 10 percent of parents of the control group public school students did so.

These findings add to a growing body of research on the effects of school choice on student achievement. Since the SCSF was founded six years ago as a philanthropic, privately funded voucher program, similar funds have offered voucher-like scholarships to students in Washington, DC, and Dayton, Ohio. The initial studies of these programs show promising results as well, as does research on students using a publicly funded voucher program in Cleveland, Ohio.


The SCSF began collecting money in 1996 to fund scholarships that would allow students in New York City public schools to attend a private or parochial school of choice. Since 1997, 1,300 vouchers have been awarded to the children of low-income families; those vouchers, which have a maximum value of $1,400 annually, are redeemable for at least three years. To be eligible for the vouchers, the student:

  • must be entering the first through fifth grades;
  • must be attending a New York City public school; and
  • must qualify for the federal school lunch program (that is, must be from a low-income family).

Between February and April 1997 alone, SCSF received 20,000 applications for the vouchers. Applicants took a baseline achievement test—the Iowa Test of Basic Skills (ITBS)—in reading and math. About 70 percent of them scored below the citywide median score on the ITBS. SCSF decided 85 percent of the vouchers awarded would go to below-average students.

The basic design of the study, conducted by Mathematica, gave the researchers a unique opportunity to assess the effectiveness of a working voucher program. A randomized lottery, conducted in May 1997, effectively assigned the students into two groups: the “experiment/treatment” group who received the vouchers, and the “control group” who did not. That design is very similar to the way researchers in the medical community assess the effectiveness of new procedures or new drugs; it is generally considered to be the “gold standard” of research protocols.

What the Research Showed

The experiment/treatment group chosen by the lottery was comprised of 1,000 families in New York City; the control group had 960 families. By virtue of the random nature of the lottery, the families in each group are not statistically different in terms of family background, income, or student achievement.

In Spring 2000, both the experiment and control groups were invited back to complete third-year follow-up questionnaires and tests. ITBS scores are reported using National Percentile Rankings (NPR) instead of raw scores. The percentile rankings show how well students perform in a particular subject relative to everyone else in the country who took the test that year. If a student received an NPR of 50 on the ITBS reading exam, for example, he or she had scored higher than 50 percent of all students taking that test.

The 2000 ITBS test scores showed the vouchers had significant effects, which were most pronounced for African-American students.

African-American students who used the voucher to go to a school of choice for three years had a composite NPR of 26.83 on their follow-up tests, compared with a control group of African-American students who had an NPR composite score of 17.60—a 9.23 percentile point difference.

The scores of African-American voucher students who had attended a school of choice for at least one year were significantly higher than those of the control group. These “part-time” voucher students had a composite NPR of 25.37, compared with a composite score of 17.82 for the control group—a difference of 7.55 percentile points.

The results are even more pronounced for math achievement. African-American voucher students who stayed in a school of choice for three years scored a full 11.80 percentile points higher on the math test than did the control group. Voucher students who had attended a private or parochial school for at least one year scored 9.65 percentile points higher in math.

The differences are somewhat lower, but still statistically significant, for reading achievement. Three-year voucher students scored 6.66 percentile points higher than did the control group, and students who had used the voucher for one or two years scored 5.45 percentile points higher.

Kirk A. Johnson, Ph.D., is a senior policy analyst in the Center for Data Analysis, and Krista Kafer is senior policy analyst for education, at The Heritage Foundation.

For more information …

The February 19, 2000, research report—”School Choice in New York City After Three Years: An Evaluation of the School Choice Scholarships Program,” by Daniel P. Mayer, Paul E. Peterson, David E. Myers, Christina Clark Tuttle, and William G. Howell—is available as Paper 02-01 from the Web site of Harvard University’s Program on Education Policy and Governance at www.ksg.harvard.edu/pepg/papers.htm.

An unabridged version of the April 12, 2002, Heritage Foundation Report—”What the Harvard/Mathematica Study Says About Vouchers and Low-Income African-American Students,” by Kirk A. Johnson and Krista Kafer—is available as Publication 02-03 from the Foundation’s Web site at www.heritage.org/library/cda/cda02-03.html.