Giving Compass' Take:

• Matt Barnum shares the results of a study that found that participation in the school voucher program in Indian negatively impacted students' math scores, and failed to impact reading scores. 

• Could the voucher system be improved, or does it need to be scrapped? 

• Learn about D.C.'s school voucher outcomes. 

Low-income students who use a voucher to attend private school in Indiana see their math scores drop for several years as a result, according to a new study.

The paper, focuses on the initial rollout of what has become the largest school voucher program in the country. In the most recent school year, over 35,000 students were enrolled in the initiative.

The study examines a few thousand low-income students who switched from public to private school using a voucher starting in the 2011-12 school year.

Notably, the authors show that low-income students who used a voucher had slightly higher starting test scores than low-income kids who stayed in public schools. This gives credence to fears that a voucher program could concentrate the most disadvantaged students in the public school system.

The authors attempt to control for these and other factors to isolate the effect of attending a private school. (Unlike some voucher studies, this paper is not able to compare students who randomly won or lost a chance to attend private school — a stronger method.)

In math, the results, which focus on grades five through eight, are consistently negative. Even four years into the program, students who use a voucher had lower test scores than public school students.

In English, there were no clear effects. Here, there was some evidence that voucher students improved over time, though there were no statistically significant positive effects after four years.

Read the full article about private school vouchers by Matt Barnum at Chalkbeat.