This paper provides a political economic analysis of Randomized Controlled Trial (RCT) experiments in international development. We argue that in more politically competitive environments, where incumbents face a higher probability of losing power, governments have stronger incentive to run RCTs and implement reforms to constrain successors' margin of policy discretion. Moreover, the effect of competition on the probability to host RCTs is stronger in more polarized societies since the incumbent's cost of losing power is higher when the opposition's ideal policies are further away. We propose a formal model and then empirically examine its theoretical predictions using a unique data set on RCTs that we have compiled. Over a cross-national panel, we find that RCTs are more likely to occur in electorally competitive jurisdictions, and that the effect is amplified by political polarization.