The paper aims to investigate the role of conceptual modelling for policy making. In particular, it is argued that the use conceptual schemas may provide an effective understanding of the information asset of Public Administration and its capacity to satisfy the needs of constituencies, thus having a public as well as social value. Consequently, the use of conceptual modelling for policy making and planning is first discussed with regard to the public sector information asset with an example from the Italian Public Administration. Then, the role of conceptual modelling for eliciting social value is considered with regard to open data. Subsequently, a case study is discussed for the open data concerning Hospitals in the United States (US), Canada, and Italy. Finally, a methodology is outlined to support public managers for choosing the data set to be “opened” and exploiting the public sector information asset under a social value perspective.