In recent years, social scientists have increasingly turned to matching as a method for drawing causal inferences from observational data. Matching compares those who receive a treatment to those with similar background attributes who do not receive a treatment. Researchers who use matching...

Does the effectiveness of a “Get Out The Vote” (GOTV) contact depend upon the method by which a voter casts a ballot? This study investigates whether those who must vote by mail are more or less responsive to an in-person mobilization message than voters who live in traditional precincts...

Voter mobilization experiments are often conducted using individual-level randomization, which can be difficult to implement. A simpler approach is to randomly assign voting precincts, rather than individuals nested within them, to treatment and control groups. Not only is it easier and...

In the social sciences, randomized experimentation is the optimal research design for establishing causation. However, for a number of practical reasons, researchers are sometimes unable to conduct experiments and must rely on observational data. In an effort to develop estimators that can...

Measuring the causal effects of digital advertising remains challenging despite the availability of granular data. Unobservable factors make exposure endogenous, and advertising's effect on outcomes tends to be small. In principle, these concerns could be addressed using randomized controlled...

Habit is a frequently mentioned but understudied cause of political action. This article provides the first direct test of the hypothesis that casting a ballot in one election increases one's propensity to go to the polls in the future. A field experiment involving 25,200 registered voters was...