Fuzzy-set method in comparative social policy: a critical introduction and review of the applications of the fuzzy-set method

This article critiques the Fuzzy-set Qualitative Analysis (fs/QCA) methodology by examining its applicability in three studies in the field of comparative social policy. In each of these three test cases, I focus on the validity of fuzzy-set’s claimed function—its ability to combine theoretic discourse and evidence analysis. All three studies investigate welfare state reform in the late twentieth century and apply fs/QCA: (1) “Welfare Reform in the Nordic Countries in the 1990s: Using Fuzzy-set Theory to Assess Conformity to Ideal Types,” (2) “States of Welfare or States of Workfare? Welfare State Restructuring in 16 Capitalist Democracies, 1985–2002,” and (3) “The Diversity and Causality of Welfare State Reforms Explored with Fuzzy-sets.” This article begins by discussing the ontology and epistemology of comparative social policy. The fuzzy set logic and set theoretic nature of social science theory is then discussed to align the ontology with fuzzy set methodology. Next, a more detailed introduction of fuzzy-set method (fs/QCA) is followed. This study suggests that fs/QCA is a unique and useful method for comparative social policy. It advances quantitative analysis by exploring cases configurationally and also advances the qualitative analysis by applying the fuzzy set logic and the principle of calibration.