Voucher Non-Portability Identification Strategy

In Simple Words

Imagine giving students a non-transferable discount coupon restricted to a specific local gym rather than an open pass to any facility. Because the coupon cannot easily be transferred to another gym, students who receive the coupon stay at their assigned local gym, while those without the coupon shop around for different clubs. This allows researchers to test whether the discount itself improves student gym attendance without the confusing side-effect of students moving to elite facilities with better workout partners.

Research question

Evaluating the direct productive impact of educational vouchers is often confounded when recipients use portable vouchers to sort into schools with higher-performing peers. An empirical strategy is required to isolate voucher mechanics when voucher portability is constrained, preventing recipients from accessing superior peer groups.

Participants

N = 1,176 human secondary school voucher applicants (1995 cohort) in Bogotá, Colombia.

Study Design

Randomized controlled trial tracking enrollment decisions 3 years post-lottery among applicants required to secure pre-lottery school acceptance.

Results

Administrative restrictions resulted in fewer than 20% of transferring students retaining their vouchers; consequently, 59.6% of voucher winners who applied to vocational schools remained in vocational schools 3 years later compared to only 42.6% of lottery losers.

Takeaway

Design school voucher evaluations by enforcing pre-lottery school selection to decouple voucher intervention effects from peer sorting variables.

Read alongside the research

Plain-English glossary

Original explanations, informed by the references below. Examples are illustrations, not data from the studies above. The research text stays unchanged.

Randomized controlled trial

A study that uses chance, like drawing lots, to decide who receives each option being compared. Researchers compare the groups’ outcomes to estimate the effect of those options.

ExampleA lottery assigns volunteers to a training programme or a comparison group. Researchers then compare their outcomes.

GET-IT glossary · Randomized study ↗Read more about randomized controlled trial →

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