Summary of impact:
This seminal paper was one the earliest efforts to understand the relationship between collaboration/ownership patterns and defects. Prior work had indicated the risks of having too many collaborators, but Bird et al brought the concept of quantifying ownership and more fine-grained data-gathering to show that it was not just the number of collaborators per se, but the quantification of the distribution of authors that were the source of the problem. This has had significant and serious implications not only on code ownership but on code review (assigning the right reviewer), continuous integration, agile development and open source contribution dynamics.
The work has been durably influential, with more than 380 citations. The follow-on work has also been quite influential – there are 20 citing papers that have over 100 citations, and 50 that have over 50 cites each. While citations present only one part of the work, this paper has been influential in studies in open source, GitHub, Alibaba, Facebook, Google, Microsoft, Huawei and other industrial organizations impacting the state of the art and practice as can been seen from its citations (papers from these organizations cite this work).