Do data availability statements increase the sharing of research data?

Abstract Background Data availability statements (DAS) are increasingly required by journals to promote transparency and reproducibility. However, it remains unclear whether their growing adoption has led to greater accessibility of research data. This study assessed trends in data accessibility, compliance with DAS, and the relationship between data sharing and citation impact in oceanographic research. Methods A total of 1 400 oceanography articles indexed in the Web of Science Core Collection were randomly selected from 2018–2024 (200 articles per year). Bibliometric characteristics, DAS presence, and actual data accessibility were recorded for each article. Data availability was classified as publicly available, available upon request, partially available, or unavailable. Corresponding authors of articles without publicly available data were contacted to evaluate data availability upon request. Associations between data availability and citation impact were examined using regression analyses. Results The proportion of articles containing a DAS increased from 11% in 2018 to approximately 50% in 2022–2024. Despite this increase, the proportion of studies with accessible data did not change over time. Publicly accessible data were available for 28.0% of articles. Among authors contacted for articles without publicly available data, only about 12% provided or were willing to provide data, resulting in accessible data for 36.6% of all articles. Marked differences in data accessibility were observed among countries and journals. Public data availability was not associated with higher citation rates overall after adjustment for journal effects, but articles with publicly available data were 51% more likely to belong to the top 10% most cited publications. Conclusions The rapid increase in DAS adoption has not been accompanied by a comparable increase in actual data accessibility. Although DAS may improve transparency of reporting, they appear insufficient on their own to promote widespread data sharing. Greater recognition of open research practices and stronger incentives for data sharing may be required to achieve meaningful progress toward transparent and reproducible science.