Read the article: "The evaluation is based on a randomized controlled trial design that compares the outcomes of eligible applicants randomly assigned to rece

Read the article: "The evaluation is based on a randomized controlled trial design that compares the outcomes of eligible applicants randomly assigned to receive (treatment group) or not receive (control group) a scholarship through a series of lotteries." Now, given lottery status parents might help their kids with HW or otherwise (b/c they don't want to waste an opportunity). I am still reading on how they control for that, but I suspect they have a TON of observables on the parents, income, location, etc. School voucher studies these days -- particularly those read and "approved" by those in the list of acknowledgements -- will go nowhere without either randomization or a suitable instrumental variable that correlates with the voucher, but not with educational outcomes. No need to throw around econometric criticisms until you read at least part of the article.