This paper reports on the first phase of an ESRC-funded research project aimed at exploring how knowledge is produced and distributed through the writing practices of academics, and how these are shaped by the contemporary context of higher education, including managerialism, and research assessment. As part of the Research Excellence Framework (REF) and to secure funding from research councils, academics are expected to demonstrate that their work has economic or social impact beyond academia. This 'impact agenda' is one of the ways in which scholarly research may engage with the notion of social justice. However, impact may be more complex in nature than is accounted for in research assessment exercises, and may be interpreted in different ways across different disciplines, with some lending themselves to social justice more readily than others. The data presented in this paper draws on interviews with academics at three different universities and in three disciplinary areas: Mathematics, History and Marketing. We discuss how they interpret policies requiring them to demonstrate economic and social impact, and how this interacts with their views on the wider role of academics in society. The findings of the project indicate that there is no unified notion of social justice across the disciplines, and that understandings of this concept, including how easily it can be achieved and the extent to which it is prioritised by the institution, influence the choices academics make in their writing practices. For example, although many of our participants talked about the importance of making their research accessible or “making a difference”, the perceived beneficiaries of this included commercial companies and government agencies. Some interpreted impact in terms of financial transparency, seeing this as a form of social justice towards students or taxpayers. Academic discipline emerged as a complicating factor in understandings of serving society, with impact being seen as more difficult to achieve in some disciplines than others. Furthermore, efforts to engage in social justice-related activities were also at times compromised by competing priorities such as demands on participants’ time. Overall, the findings indicate that the valued forms of knowledge creation in the working lives of our participants are complex and contested. The ways in which social justice is conceptualised by our participants and how it serves as a driver for the choices they make, interact with their disciplinary traditions, their career stage, and personal priorities, as well as how they interpret policy on impact.