Case Studies and Theory Development in the Social Sciences - Alexander L. George [123]
What Is Typological Theory?
In contrast to a general explanatory theory of a given phenomenon, typological theory provides a rich and differentiated depiction of a phenomenon and can generate discriminating and contingent explanations and policy recommendations.
We define a typological theory as a theory that specifies independent variables, delineates them into the categories for which the researcher will measure the cases and their outcomes, and provides not only hypotheses on how these variables operate individually, but also contingent generalizations on how and under what conditions they behave in specified conjunctions or configurations to produce effects on specified dependent variables.464 We call specified conjunctions or configurations of the variables “types.” A fully specified typological theory provides hypotheses on all of the mathematically possible types relating to a phenomenon, or on the full “property space,” to use Lazarsfeld’s term. Typological theories are rarely fully specified, however, because researchers are usually interested only in the types that are relatively common or that have the greatest implications for theory building or policymaking.
Typological theories specify the pathways through which particular types relate to specified outcomes. Such pathways are analogous to syndromes in pathology. A disease may arise through different causal paths, and it may exhibit varying symptoms and degrees of severity, so pathologists speak of syndromes—clusters of causes and outcomes—rather than a single manifestation of a particular disease. Typological theory is similarly open to the possibility of equifinality—the same outcome can arise through different pathways.465 For example, one typological theory on de-terrence, instead of simply addressing “deterrence failure,” specifies different kinds of deterrence failure: failure through fait accompli, limited probes, or controlled pressure.466
Typological theories differ from historical explanations of a particular event. A historical explanation refers to a series of specific connections in an extant historical case, often supported by relevant theories. In contrast, typological theory identifies both actual and potential conjunctions of variables, or sequences of events and linkages between causes and effects that may recur. In other words, it specifies generalized pathways, whether the path has occurred only once, a thousand times, or is merely hypothesized as a potential path that has not yet occurred. A pathway is characterized in terms of variables, often with nominal cut off points distinguishing among types but sometimes with ordinal or interval cut off points, rather than by the values of these variables associated with a historical case. For example, instead of focusing on the Russian Revolution per se, a typological theory might explain this revolution as one example of the type of revolution that follows an international war; replaces weak state institutions; and takes place amidst an economic crisis. Even if there is only one revolution fitting this type, identifying the conjunctive effects of its underlying causal mechanisms allows us to generalize in a limited way to possible future revolutions that fit the same type.467
Such generalized pathways are what is distinctive about typological theory. They are abstract and theoretical even though they are closer to concrete historical explanations than are claims about causal mechanisms. 468 Specific pathways, in turn, can be supported by extant hypotheses on causal mechanisms. Cognitive dissonance theory and prospect theory, for example, provide causal mechanisms that support explanations of recurring patterns of behavior under certain conditions.
Typological theories are often constructed and refined through case study methods; they can also benefit from quantitative methods and formal models. The