Causal evidence of racial and institutional biases in accessing paywalled articles and scientific data

Scientific progress depends on researchers' ability to access and build upon the work of others. Yet, much published work remains behind expensive paywalls, and even accessible articles often rest on datasets shared only "upon reasonable request" to the authors. Researchers can try to overcome these barriers through informal channels, such as emailing authors directly, but whether such channels are hindered by racial or institutional biases remains unknown. Here we combine survey data, semi-structured interviews, large-scale observational analysis, and two randomized audit experiments to examine disparities in access to scientific knowledge. Surveyed researchers in the Global South report markedly lower institutional access to the literature and depend more heavily on informal channels to obtain papers and data; interviews elaborate the workarounds and racialized frictions they encounter. Our analysis of 250 million articles reveals that Global South researchers cite paywalled papers at significantly lower rates than Global North counterparts--a gap associated with reduced knowledge breadth and scholarly impact. Using citation-context classification, we further find that papers whose data is available only upon request are less likely to be cited for reusing their data, a penalty falling disproportionately on the Global South. To probe mechanisms, we conduct two email audit studies in which fictional PhD students differing in racial background and institutional affiliation request paywalled articles (N = 18,000) and datasets (N = 16,000). Racial identity influences response rates to both requests, whereas institutional affiliation influences access to datasets. These findings reveal how informal gatekeeping can perpetuate structural inequities in science, highlighting the need for stronger data-sharing mandates and more equitable open-access policies.