NBER Publications by David Sims

Educational interventions are often narrowly targeted and temporary, and evaluations often focus on the short-run impacts of the intervention. Insofar as the positive effects of educational interventions fadeout over time, however, such assessments may be misleading. In this paper, we develop a simple statistical framework to empirically assess the persistence of treatment effects in education. To begin, we present a simple model of student learning that incorporates permanent as well as transitory learning gains. Using this model, we demonstrate how the parameter of interest – the persistence of a particular measurable education input – can be recovered via instrumental variables as a particular local average treatment effect. We initially motivate this strategy in the context of tea...