Abstract
The operationalization of Findable, Accessible, Interoperable, and Reusable (FAIR) data principles within social science repositories presents distinct challenges due to qualitative methodological heterogeneity, complex privacy constraints, and evolving institutional mandates. This study investigates the alignment between formal data management policy frameworks and the grassroots curation practices of academic librarians across twenty-four dedicated social science data repositories in North America and Europe. Utilizing a mixed-methods comparative design, we evaluated repository policy documentation against an empirically grounded FAIR operationalization matrix and conducted structured interviews with forty-two practicing data curators and subject librarians. The findings reveal a marked divergence between institutional policy articulation and practical workflow execution, particularly in the domains of interoperability and granular metadata reuse. While findability and access controls are heavily codified and executed via persistent identifiers and regulated access tiers, semantic interoperability remains impeded by inconsistent schema crosswalking and non-standardized qualitative data documentation. Academic librarians frequently compensate for policy ambiguities through ad-hoc curation interventions, mediating ethical access and technical validation without adequate infrastructure or institutionalized procedural support. We propose an integrative framework that harmonizes institutional policy design with practical librarian-mediated workflows to advance FAIR compliance across the social sciences.