Today, findings from the Forum's 11th annual census of voucher schools reveal a likely contributing factor for the test score similarities--in many ways voucher schools and MPS schools are alike:

The student population in the average voucher school is 78% voucher students, who must be low-income to be eligible for a voucher. The student population at the average MPS school is 77% low-income, as measured by eligibility for free or reduced-price lunch.

The student population at the average voucher school is also 85% minority, while the average in MPS is 88% minority.

Voucher schools average 15.6 students per full-time teacher, compared to 14.9 students per full-time MPS teacher.

In addition, while MPS students must take the state standardized exam (the WKCE) of the 122 voucher schools, 114 administer standardized exams, and less than half of those (53) administer the WKCE.

Among the middle, elementary, and K-12 voucher schools, less than half have teaching staffs large enough for each grade level to have at least one full-time teacher.

On the aggregate, high school students who use vouchers appear to drop out over the course of four years at a much lower rate than MPS high school students.

Because the Forum has been surveying voucher schools for 11 years now, we can make some observations about how the voucher program has changed over the past decade. Enrollment has grown 227% since 1998-99, to over 20,200 voucher students in 2008-09 (the annual price tag for the program has grown 358% to $129.1 million this year).

Since the growth in enrollment has been accompanied by an increase in the number of schools, from 86 to 122, the average school size has grown just 5%, from 201 students to 211. At the same time, the average rate of voucher use within a school has grown from 34% to 78%.

The concentration of voucher students across the program has not changed dramatically, however. Today, just as in 1998-99, a fifth (20%) of the schools enroll half (50%) of all voucher students. The greatest difference is in the share of students enrolled in non-denominational Christian schools, which was 1% in 1998-99 and is 17% today. In addition, the percent of voucher students attending secular schools has declined from 33% to 19% over the past decade.

We also find that the distribution of schools and students across the city has changed. There are 10 fewer voucher schools on the city's south side today, at 15 schools, while the number of schools on the northwest side has doubled, to 57 schools.