Extant Information Systems research emphasizes the strategic benefits of digitalization and value co-creation for business. Less is known, however, about the dynamics of how value is co-created in the digitalization of the public sector, where data infrastructures are increasingly adopted. We identify three core empirical challenges for value co-creation in the public sphere, corresponding to the following conceptual tenets: participation in infrastructuring processes, data curation, and data protection. We propose to draw on the Participatory Design tradition that permeates the Information Systems field in Scandinavia to critically harness the political meaning of value co-creation. Drawing on a two-year project on the design of data infrastructures in three areas of the public domain (environmental monitoring, healthcare, and smart cities), we contribute to Information Systems by proposing a research agenda consisting of three future directions for critical studies of value co-creation in data infrastructures in the public sector.