Teacher librarians and reading scores study

Full-time school librarians linked to higher student reading scores
Research findings indicate that Colorado schools that either kept or acquired a full-time school librarian between 2005 and 2011 tended to have more students scoring higher in reading in 2011 and fewer students scoring unsatisfactory, compared with schools that either lost their librarians or never had one.
Lance, K., & Hofschire, L. (2011). Change in School Librarian Staffing Linked with Change in CSAP Reading Performance, 2005 to 2011. Denver, CO: Library Research Service.
http://www.lrs.org/documents/closer_look/CO4_2012_Closer_Look_Report.pdf