The exponentially growing production of data enables global connectivity as well as increased openness and sharing, which turn into a powerful force that is changing the global economy and society. Governments around the world have become active participants in this evolution by opening up their data for access and re-use by public and private agents alike. The recent phenomenon of Open Government Data (OGD) has spread around the world, driven by the proposition that opening government data has the ability to generate both economic and social value. However, a review of the academic research and the popular press reveals only sporadic attention given to various aspects with no overarching framework that explains how OGD generates value. We apply a critical realist approach to uncover the generative mechanisms that serve to explain this relationship. First, we present a strategic framework with four archetypical generative mechanisms. The framework outlines the different pathways to value generation an d highlights the current tension between the private/public and economic/social domains. Second, we offer a conceptual model that provides a systematic way of articulating and examining further the generation of value from OGD.