Political scientists often analyze data in which the observational units are clustered into politically or socially meaningful groups with an interest in estimating the effects that group-level factors have on individual-level behavior. Even in the presence of low levels of intracluster...

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...