QCA, 25 Years after “The Comparative Method”: Mapping, Challenges, and Innovations—Mini-Symposium.

This paper introduces the mini-symposium on Qualitative Comparative Analysis (QCA) and set-theoretic methods, both crisp sets and fuzzy sets, and situates the different contributions in a wider methodological debate concerning cross-case analysis. The paper argues that QCA is not just a set of techniques, but a distinctive research approach, with its own goals and set of assumptions. Concerning the wide methodological debate, special attention is paid to the added value of QCA and specific innovations introduced in the mini-symposium.This essay contrasts the conventional template for conducting social inquiry and the alternate template provided by configurational, case-oriented analytic methods, first formalized in The Comparative Method. The essential contrasts address the fundamental building blocks of social research, ranging from the definition of relevant cases to the understanding of social causation. The alternate template described in this essay provides a much stronger basis for the articulation of within-case and cross-case analysis than is offered by the conventional template.This article provides a first systematic mapping of QCA applications, building upon a database of 313 peer-reviewed journal articles. We find out that the number of QCA applications has dramatically increased during the past few years. The mapping also reveals that csQCA remains the most frequently used technique, that political science, sociology, and management are the core disciplines of application, that macrolevel analyses, medium-N designs, and a mono-method use of QCA remain predominant. A particular focus is also laid on the ratio between the number of cases and number of conditions and the compliance to benchmarks in this respect.QCA’s ability of addressing complex theoretical expectations and taking account of configurational relationships is rarely fully exploited. Assessing comparative welfare-state research, which has employed QCA, we find that only about half of the studies reviewed have expressed complex theoretical propositions in set-theoretical terms, revisited cases subsequent to the formal analysis, or subjected findings to robustness checks. We discuss the relevance of each of these three aspects and argue that carefully considering these will improve the quality of QCA applications.Contrasting insights that can be gained from large-N QCA and econometric analysis, we outline two novel ways to integrate both modes of inquiry. The first introduces QCA solutions into a regression model, while the second draws on recent work in lattice theory to integrate a QCA approach with a regression framework. These approaches allow researchers to test QCA solutions for robustness, address concerns regarding possible omitted variables, establish effect sizes, and test whether causal conditions are complements or substitutes, suggesting that an important way forward for set-theoretic analysis lies in an increased dialogue that explores complementarities with existing econometric approaches.This paper discusses five strategies to deal with five types of errors in Qualitative Comparative Analysis (QCA): condition errors, systematic errors, random errors, calibration errors, and deviant case errors. These strategies are the comparative inspection of complex, intermediary, and parsimonious solutions; the use of an adjustment factor, the use of probabilistic criteria, the test of the robustness of calibration parameters, and the use of a frequency threshold for observed combinations of conditions. The strategies are systematically reviewed, assessed, and evaluated as regards their applicability, advantages, limitations, and complementarities.Current standard practices put sufficiency at the core of Qualitative Comparative Analysis (QCA), while the analysis of necessity is limited to the test for necessary conditions. Here, we argue that the possibilities of QCA in the latter domain are much greater. In particular, it can be used to ... [ABSTRACT FROM PUBLISHER]