This study examines the influence of four predictor variables—university-wide research activity, faculty status (eligibility for sabbaticals), university control (public versus private), and enrollment—on the scholarly productivity of librarians at research universities in the United States. University-wide research activity is directly related to librarians’ scholarly productivity, although the relationship weakens at institutions with more than 30 librarians. In contrast, faculty status has a direct influence that is strong and consistent across all university sizes. These results suggest that the faculty subculture, by setting university-wide expectations for research, influences librarians’ scholarly productivity only when there is no strong librarian subculture with its own research norms—in other words, only when the institution employs relatively few librarians. Librarians’ faculty status (or nonfaculty status) appears to have both formal aspects (such as promotion requirements), which are consistent across all university sizes, and informal aspects (such as scholarly norms and expectations), which moderate the influence of the faculty subculture at those institutions where the librarian subculture is strong.