Qualitative comparative analysis (CQA): State of the art and prospects

Qualitative Comparative Analysis (or QCA; Ragin 1987; Ragin and Drass 1994) and its successor, Fuzzy Set Qualitative Comparative Analysis (fsQCA; Ragin 2000; Ragin, Drass, and Davey 2004; Ragin 2004a), were both developed for the analysis of small-and intermediate-N data sets, typical of those used by researchers in comparative politics and related disciplines. These techniques are designed to unravel causal complexity by applying set-theoretic methods to cross-case evidence. Their central goal is to mimic some of the basic analytic procedures that comparative researchers use routinely when making sense of their cases.  The key difference between QCA and traditional case-oriented methods is that with QCA it is possible to extend these basic analytic procedures to the examination of more than a handful of cases, for example, to more than 10.2  In fact, there is no procedural limit on the number of cases that can be studied using QCA.