Quinn Galbraith, Elizabeth Smart, Sara D. Smith and Megan Reed have published "Who Publishes in Top-Tier Library Science Journals? An Analysis by Faculty Status and Tenure" in College & Research Libraries.
Here's an excerpt:
This study analyzes the status and background of authors publishing in high-impact library science journals. Twenty-three high-impact journals were selected in this study by both quantitative and qualitative measures, while the analysis of author background focuses on whether the author holds a faculty status position with a tenure track. This study finds that 76 percent of academic librarians have faculty status.