The Sensitivity of Impact Estimates to Data Sources Used: Analysis From an Access to Postsecondary Education Experiment

Abstract

Background: This article reports on the Future to Discover Project—a Canadian randomized controlled trial of two high school interventions—where data on key postsecondary enrollment outcomes were collected for two phases. During the initial phase, outcomes were recorded from administrative data and follow-up surveys. During the later phase, data came from administrative records only. Objectives: The article provides analyses that are informative about the consequences of a change from administrative-only data to survey-only data (and vice versa) for the estimation of impacts. Results: The change from administrative-only to survey-only data tended to produce apparent drops in postsecondary enrollment rates that varied by subgroup and education outcome. Nonetheless, levels and significance of impact with respect to postsecondary enrollment remained relatively stable. Conclusions: The findings of the article provide evidence that estimating education program impacts in the context of a randomized experiment can be relatively robust to the data sources chosen. They suggest that internal validity and conclusions for policy need not be affected by changing data sources even when the change produces marked changes in levels of the outcome of interest observed.