Roman, Caterina G., Hannah J. Klein, and Kevin T. Wolff (2017). Quasi-experimental designs for community-level public health violence reduction interventions: a case study in the challenges of selecting the counterfactual. Journal of Experimental Criminology, First Online: November 6, 2017.
It is important to carefully consider the unit of analysis for measurement of comparison communities. Assessing the geographic clustering of matched communities to mirror that of the treated community holds conceptual appeal and represents a strategy to consider when evaluating community-level interventions taking place at a large scale. Regardless of the final decisions made in the selection of the counterfactual, the field could benefit from more systematic diagnostic tools that document and guide the steps and decisions along the way, and ask: “could there have been another way of doing each step, and what difference would this have made?” Overall, across community-level evaluations that utilize quasi-experimental designs, documentation of the counterfactual selection process will provide a more fine-grained understanding of causal inference.