Organising and participating in Knowledge Exchange (KE) events represent a considerable commitment by social science academics. Yet academics' participation in KE activities is not professionally rewarded as are other academic endeavours, so why do they do it? Understanding academics' perspectives regarding their own motivations for engaging in KE activities is a lacuna within the literature which this article begins to address. Drawing on qualitative interview data with social scientists working within the Centre for Population Change (CPC), the analysis presented in this paper develops a typology of academics' motivations for committing to organise and host KE events. These are: (1) contractual obligation to research funders; (2) professional self-interest; (3) to recompense society. Their narratives are interpreted through a conceptual framework of the institutionalisation of KE practices through the impact agenda which has shifted institutional expectations and professional norms regarding 'good academic practice' within contemporary academia. This paper concludes that the institutional, political, and cultural landscape in which KE events exist has considerable consequences for how academics come to commit to such activities. Understanding this environment can add to our understanding of why academics participate in KE events, and thus why they happen at all.