“…The growth in the use of spatial econometric models in political science is partly a consequence of improvements in the techniques used to estimate and interpret increasingly complex specifications (e.g., Beck et al, 2006;Franzese and Hays, 2006;Ward and Gleditsch, 2008;Darmofal, 2015). Though the theories used to justify spatial models are varied (see e.g., Shipan and Volden, 2008, for policy diffusion), these models typically focus on three types of spatial processes (Cook et al, 2015): clustering in the outcomes (i.e., when y i influences y j and vice versa), clustering in the unobservables (i.e., when ϵ i is correlated with ϵ j ), and clustering in the observables (i.e., when x i influences y j ). Most political science research has focused on two particular models, the SAR and the spatial-X (SLX) models.…”