Where does the money go? Impact of sponsorship-based funding on contribution behaviour in knowledge-sharing platforms

This paper examines how the introduction of sponsorship-based funding for open-source software contributors alters their
contributions in the knowledge-sharing ecosystems. While sponsorship support to the contributors is expected to increase their contributions to the host platform, it is unclear (a) how it would lead to reallocation of their efforts between core and non-core contributing activities on the host platform, and (b) whether the effort reallocation between core and non-core contributing activities spills-over to other related knowledge-sharing platforms where the contributors receive no funding. In this paper, we seek to answer the two research questions by leveraging a sponsorship based funding feature that was introduced by GitHub in May 2019. We collect contributor-level data from both the host platform (GitHub, or GH) and a related knowledge-sharing platform (StackOverflow, or SO).
Our empirical results show that a contributor’s sponsorship listing on GH has no effect on the core, development-related contributions, but only increases non-core contributions (maintenance related tasks). We attribute the effort reallocation between core and noncore contributing activities to the different (intrinsic vs. extrinsic) motivations that drive the core and non-core contributing activities.
Furthermore, we find evidence of effort distortion that leads to a negative spillover effect on contributions that occur on SO. Interestingly, we find that this negative spillover effect on SO is restricted to core contributing activities (i.e. answers), resulting in a similar effort reallocation pattern where the sponsored contributors shift their efforts relatively towards non-core contributing activities. We discuss the important implications of these findings to platform owners and contributors in the online communities.