Please direct correspondence to florentine.maier@wu.ac.at.Abstract: NPOs and their funders are increasingly drawn to the Social Return on Investment (SROI) method to evaluate the social impact of programs, organizations or organization networks. While many claims about the benefits of SROI have been expressed, various points of criticism have also been raised.On the basis of both current research and our own experience in conducting SROI analyses, we develop a comprehensive assessment of this method, which is structured along two dimensions: the observer's paradigmatic perspective, on the one hand, and positive or negative valuation, on the other. We identify two major merits: SROI analysis can provide legitimacy to NPOs or their funders, and it can assist in allocating resources. We identify limitations from three perspectives: From an interpretative-sociological perspective, criticism of commensuration and utilitarianism calls the method as a whole into question.From a technical-instrumental perspective, there are a number of difficulties that could however be overcome as the method matures. From an intermediary perspective, a number of limitations become apparent that, while inherent to SROI analysis, are no reason for abandoning it, as long as they are thoroughly understood. We conclude by providing suggestions for the responsible use of SROI analysis.The question of how to advance the common good is increasingly seen as a matter of finding out and implementing "what works" rather than of following ideologies. Among NPOs and government institutions that consider themselves cutting-edge, the formulation of explicit theories of change (see, for example, Fulbright-Anderson & Auspos, 2006) as well as the regular development of evidence-based policies (Pawson, 2006:vii) are expected. In managing performance, the focus has clearly shifted from inputs and outputs to impacts and public value (Barman, 2007; Lynch-Cerullo & Cooney, 2011; Moore, 2013). On the one 1 hand, these developments are to be welcomed as progress towards more open-mindedness and discursive rationality. On the other hand, the ideology of anti-ideology comes with its own trappings. The old quip that "[p]ractical men, who believe themselves to be quite exempt from any intellectual influence, are usually the slaves of some defunct economist" (Keynes, 1965:383) still applies. The present article contributes to a deeper understanding of this dilemma by focusing on a particular method that is widely used in the search for impact and evidence: the analysis of Social Return on Investment (SROI). It is the aim of this paper to contribute to a balanced and comprehensive understanding of its merits and limitations.Out of more than 40 approaches that have been developed for measuring social impact (Stevenson, Taylor, Lyon, & Rigby, 2010), SROI analysis is one of the most widespread. It is a mixed-method-approach to assess the social, economic, and environmental impact of interventions. Its most prominent feature is the SROI ratio. This ratio aims to dete...