Can defaults change behavior when post-intervention effort is required? Evidence from education

Little is known about the effectiveness of defaults whenmoving the target outcome requires substantial post-intervention effort. In two field experiments, we change the university exam sign-up procedure to “opt-out” for a single exam (Exp1), and for many exams (Exp2). Both interventions increase sign-up at the beginning of the semester. Downstream, at the end of the semester, opt-out increases exam participation for a single but not for many exams. For the single exam, effects on passing are heterogeneous: students responsive to unrelated university requests convert increased sign-ups into passed exams. For non-responsive students, increased sign-ups result in failed exams due to no-shows. Defaults can thus be effective but need to be carefully targeted.