This paper examines the methodological strengths and weaknesses of contribution analysis (CA), awarding particular attention to the ability of CA to identify and determine the extent of influence from alternative explanations. The author argues that CA – in its current form and application – fares well in terms of identifying salient external factors, but finds itself in need of further methodological elaboration to adequately account for the extent of influence from these factors. As such, CA remains vulnerable to threats of internal validity. In strengthening the merit of causal claims based on CA, focus should not only be directed at CA as an analytical strategy but should also involve a much broader discussion on how to (re)think validity in the context of evaluation. An outline of the implications of this new categorization for causal claims based on CA and a discussion of how to enhance the credibility of CA concludes the paper.
The paper by Sebastian Lemire was presented at the 9th EES Biennial Conference: Evaluation in the Public Interest - Participation, Politics and Policy.