Combining the Strengths of Qualitative Comparative Analysis with Cluster Analysis for Comparative Public Policy Research: With Reference to the Policy of Economic Convergence in the Euro Currency Area

Qualitative Comparative Analysis (QCA) is a well-established method for comparing national public policy similarities and differences. It is argued that Cluster Analysis can add additional benefits to such research when used concurrently with QCA. Cluster Analysis provides a better method for the initial exploration of multivariate data and examining how countries compare because it can work with the full range of available interval data while patterns are created and viewed. This provides the best first method for exploring patterns and likely groupings of countries. QCA then provides a more robust method for theorizing about the construction of such groupings and their relationship around similar variable scores. QCA makes such theorizing transparent. The research example used to illustrate the benefits of combining Cluster Analysis and QCA is an analysis of the evolving of macroeconomic policy for the countries sharing the Euro, comparing 2005 (precrisis) with 2010 (postcrisis).