If similarity is the challenge - congruence analysis should be part of the answer

Abstract: This contribution to the debate on the challenges to comparative politics largely focuses on the issue of differences versus similarities, the issue that has been raised by both authors: Caramani and Van Kersbergen. I share their concern that too much research focuses on differences between countries and I also join them in locating the sources of this bias in methodological considerations. I do not agree however with some of Caramani¿s points, in particular his fundamental claim that explanation necessarily demands variations across cases; a claim that seems also to be made at least implicitly by Van Kersbergen. I argue that the validity of an explanation rather depends on the degree to which empirical evidence is congruent with observable implications of this explanation and is not congruent with implications of rival explanations. It is irrelevant whether these theoretical expectations concern differences or similarities between countries. I therefore advocate a theory-driven rather than a case-driven analysis of national political systems in order to meet the challenge to explain similarities between them. Key words: case study; comparative method; comparative politics; research design