Generative AI tools are increasingly used in software development and have been associated with benefits such as faster task completion and improved perceived productivity. However, whether these benefits extend across different developer populations remains unclear. This is especially relevant for developers with disabilities, whose work can already be impacted by accessibility barriers. Yet, evidence remains limited across a broader range of disability groups. This study investigates whether the wider availability of GitHub Copilot is associated with changes in productivity among GitHub users who self-identify as having a disability. Using publicly available profile and repository data, we curated a dataset of 199 developers across multiple disability groups and compared their activity before and after GitHub Copilot became freely available. We found that most disability groups showed a descriptive pattern of fewer commits but more code modified. In several disability groups, the distribution of developers across commit activity levels shifted toward both lower and higher level, leaving fewer developers at moderate level. However, we found no evidence that changes in commits or net lines modified differed across disability groups. These findings suggest that the wider availability of GitHub Copilot cannot be associated with a broad increase or decrease in observable development activity, while patterns of change varied across developers and disability groups.
Psychological safety (PS) refers to the belief that team members can speak up, ask questions, and make mistakes without fear of negative consequences. Although PS has been studied in traditional software teams, less is known about how it may appear in pull-based open-source software development, where contributors are self-directed and often collaborate voluntarily. This paper introduces a theory-informed framework for understanding how PS may be reflected in pull request (PR) interactions. We investigate the framework through a mixed-methods approach combining repository-based analysis and a survey of OSS contributors. First, we constructed a PS index using nine observable PR interaction indicators extracted from 60,685 PRs across 26 GitHub repositories. Second, we surveyed 57 OSS contributors about their perceived PS and experiences of corresponding PR interactions. All nine surveyed interaction indicators were significantly and positively associated with perceived PS. However, the repository-based index was not significantly associated with survey-reported PS. Contributors' open-ended responses further highlighted the importance of feedback quality, opportunities to participate, and how PR outcomes are interpreted. Together, our framework and mixed-methods findings provide initial insights into how PS may be reflected in PR interactions, highlighting the importance of both PR interaction patterns and contributors' experiences.