Social and solidarity economy organisations are under increasing pressure to demonstrate their social and wellbeing outcomes. Still, the lack of a clear and agreed definition of social value creation makes it difficult to translate social value into meaningful practices for measuring, managing and reporting impact. Social and solidarity economy organisations can choose to proactively and voluntarily embrace social impact measurement for learning and promotional purposes. Yet, research shows that institutional demands, particularly from external funders, are the main factor affecting their methodological choices. Hence, there is a need to mainstream social impact measurement approaches among social and solidarity economy organisations as well as to adapt them to their capacities and needs, which may be different from traditional impact investing metrics. This session will showcase new OECD work in the field and discuss with leading experts and practitioners how to ensure effective social impact measurement for the social and solidarity economy. Key questions: • Why is it important that the social and solidarity economy more widely adopts a social impact measurement culture? How can policy makers and others facilitate and support this? • Which methodologies are better suited to fully capture the multiple impacts of the social and solidarity economy while allowing for greater and more comparable evidence? • How are current social impact measurement practices helping social and solidarity economy organisations make their impact credible and visible? To what extent are the existing methods and tools adapted to their capacity and needs?