Size Doesn't Matter: In Defense of Single-State Studies

Abstract Despite the bias against such studies in our discipline, we argue that research designs focusing on a single state are sometimes preferable to those employing data from all 50 states. Single state studies are appropriate when the researcher wishes to generalize to a unit of analysis other than the states themselves, when conditions in a given state provide a unique opportunity for the most rigorous test of a hypothesis, and when the measurement advantages of a single-state study outweigh the costs of limited generalization. We draw on a range of literature to reinforce our primary contention, that it is soundness of theory and rigor of analysis, rather than the number of states, that makes research valid and important.