The latest from the Assessment in Action program (http://www.ala.org/acrl/AiA) is a report which summarises key evidence from the two years of the AiA project (a US project about evaluating impact and value of libraries in Higher Education). The report title is fairly self-explanatory:
Brown, K. and Malenfant, K. (2016) Documented library contributions to student learning and success: Building Evidence with Team-Based Assessment in Action Campus. Projects http://www.ala.org/acrl/files/issues/value/contributions_y2.pdf
One of the conclusions is that "Information literacy instruction strengthens general education outcomes. Several AiA projects document that libraries improve their institution’s general education outcomes and demonstrate that information literacy contributes to inquiry-based and problem-solving learning, including critical thinking, ethical reasoning, global understanding, and civic engagement."
There is a reflection on the report from Barbara Fister, here: https://www.insidehighered.com/blogs/library-babel-fish/lasting-value-libraries
Photo by Sheila Webber: luminous pegs on the clothes hanger, April 2016