Before revision:  We revisit two strands of the empirical literature on persuasion to show that the persuasive effect is highly heterogeneous and studies based on binary instruments provide limited information about the average persuasion rate in a heterogeneous population.
After revision:  We revisit the empirical literature on persuasion to show that the persuasive effect is highly heterogeneous and studies based on binary instruments provide limited information about the average persuasion rate in a heterogeneous population.