The Enduring Indispensability of the Controlled Comparison

Abstract

Do controlled comparisons still have a place in comparative politics? Long criticized by quantitatively oriented methodologists, this canonical approach has increasingly been critiqued by qualitative methodologists who recommend greater focus on within-case analysis and the confinement of causal explanations to particular cases. Such advice accords with a welcome shift from a combative “tale of two cultures” toward mutual respect for research combining qualitative and quantitative methods in the simultaneous pursuit of internal and external validity. This article argues that controlled comparisons remain indispensable amid this “multimethod turn,” explicating how they too can generate both internal and external validity when their practitioners (a) craft arguments with general variables or mechanisms, (b) seek out representative variation, and (c) select cases that maximize control over alternative explanations. When controlled comparisons meet these standards, they continue to illuminate the world’s great convergences and divergences across nation-states in a manner that no other methods can surpass.

The Comparative Method in Practice: Case Selection and the Social Science of Revolution

“…With such a long tradition of articulation, it is easy to assume that comparative methodology is a completely institutionalized form of analysis. In fact, this is exactly what some comparativists argue (Bennett and Elman 2007;Goodwin and Horowitz 2002;Mahoney 2007;Rihoux et al 2013;Slater and Ziblatt 2013).…”

“…Yet a danger for the subfield lies in too quickly assuming that repeated results mean a substantiated theory. For instance, findings from a comparative study are only portable to the extent that the selection of its cases allow for such inferences to be made (Goodwin 2001;Skocpol and Somers 1980;Slater and Ziblatt 2013). But as we have seen, practitioners select their cases for a variety of purposes besides portability.…”

“…This is most famously practiced by Skocpol (1979:41), who considered the social revolutions of France, Russia, and China so similar that it was ""more than sufficient to warrant their treatment together as one pattern calling for a coherent causal explanation." Also popular is the strategy of controlling for exogenous environments of time or place (see Slater and Ziblatt 2013). For example, Goldstone (1991) examines cases of state breakdown in the early modern era, and Goodwin (1989:61-62) emphasizes that "A regional approach allows one to 'control' for a variety of factors that one might otherwise mistake as causally significant.…”

“…The sharp criticisms engendered a wave of responses from comparativists, which have done much to articulate and formalize the methodology (e.g., Brady and Collier 2004;George and Bennett 2005;Gerring 2007;Goertz and Mahoney 2012;Mahoney and Rueschemeyer 2003;Ragin 2008). As a result, comparative methodologists have claimed victory of a sort, arguing that their methods have increased in rigor and are a standard option for researchers across the social sciences (Bennett and Elman 2007;Mahoney 2007;Rihoux et al 2013;Slater and Ziblatt 2013). Studies of revolution have been intimately connected to the development of comparative analysis in the social sciences.…”

Composite and Loose Concepts, Historical Analogies, and the Logic of Control in Comparative Historical Analysis

“…The point here is not that general categories and analytical distinctions should be avoided in comparative historical analysis. Przeworski and Teune (1970, p. 25) are correct to point out that " [t]he bridge between historical observations and general theory is the substitution of variables for proper names of social systems in the course of comparative research"-a conclusion that also holds for the use of the logic of controlled comparison (Slater and Ziblatt 2013, p. 1306). …”