Voucher Plans' Test Data Yield Puzzling Trends

By Debra Viadero

The latest results from a pair of studies of school choice programs in New York City and the District of Columbia raise as many questions as they answer about what happens when students are given vouchers to help pay for their private school tuition.

According to the data, black students in New York City who took advantage of privately financed scholarships to private schools scored significantly higher after three years—as much as 9 percentile points—than their peers who had applied to the program but were turned down.

The same pattern did not hold, though, for African-American students taking part in a similar program in the nation's capital or for Hispanic...