Efficiency evaluations of North American university libraries by data envelopment analysis

A method for ranking efficient decision making units in Data Envelopment Analysis is suggested. The method uses parametric programming and calculates "rigidity" of efficient units relative to perturbations of input and output data.;Theoretical results are applied to 108 North American university libraries. The efficiency of the libraries is determined by the Charnes-Cooper-Rhodes tests. The radius of rigidity approach is applied to efficient libraries. In particular, we focus on the McGill University library and compare its efficiency to other libraries using different data sets.