Typological Theory

A generic typological analysis (see the typological-analysis entry) is primarily descriptive: it sorts cases into categories or ideal types to organize and describe variation. Typological theory is explanatory — each type is a combination of explanatory variables tied to a hypothesized outcome and causal logic, so the typology functions as a structured theory rather than a filing system. In other words, typological theory adds causal claims and contingent generalizations to the classificatory move, and it is explicitly designed for theory building with case studies.

A property space is the multidimensional grid formed by cross-tabulating the values of the explanatory variables; each cell is a logically possible combination. With several variables the number of cells multiplies quickly, and many are empirically empty or logically impossible. Elman recommends compressing and pruning the space — merging redundant cells and dropping impossible ones — so the typology stays tractable and meaningful while still representing the combinations that drive the outcome, balancing analytic richness against the limited-diversity problem.

Both are configurational and treat combinations of conditions as causes, and both confront limited diversity (empty cells or logical remainders). QCA formalizes the analysis with set-theoretic calibration and Boolean minimization to derive sufficient combinations, whereas typological theory emphasizes building and interpreting an explanatory property space and pairing it with within-case analysis. They are complementary: a typological theory can structure the conditions and types, while QCA can systematically test which configurations are necessary or sufficient across the cases.