Partnerships can be found in many areas of social and economic life. These arrangements have become particularly common in research and development activities where organizations increasingly look for partners to complement their own technological capabilities with a view to create innovative products and processes. R&D partnerships, however, are fraught with challenges because the conditions for creativity through cooperation are still not fully understood. Academic partnerships are also very common and offer a fertile ground for investigation. Academic cooperation takes many different forms and results in a wide range of outcomes (Laband and Tollison, 2000). One of the most visible outcomes is co-authored publications (Melin and Persson, 1996). Nowadays, there is extensive data available about both the context of these partnerships as well as the quality of their outcome. This paper explores the determinants of the gain for authors who cooperate through co-authorship in the publication of academic articles. We distinguish between short-term benefits (i.e. the increase in citations of the co-authored article relative to the authors' previous publications) and the long-term ones (i.e. the increase in citations of articles subsequent to the co-authored piece). We find evidence that these benefits have different determinants for co-authors depending on their past experience. While co-authorship generally seems to benefit more the junior (younger and with a lower academic reputation) author, the senior partner can reduce the gap with a strong personal track record and co-authoring experience.