A study reported in 1978 of 23 middle managers and 11 administrators in 5 Association of Research Libraries libraries as well as a review of ads for 82 middle managerial positions in academic libraries posted in 1975 showed that43 (52.4%) of the ads listed an ALA-accredited library master's degree as a qualification, 37 (45.1%) listed library master's degree without specifying ALA-accredited, 30 (36.6%) listed second master's degree, 4 (4.9%) listed Ph.D., 1 (1.2%) listed an other professional degree, and 1 stated that a master's degree was not required. (Source)
Ibid…. showed that, of 23 middle managers, 21 (91.3%) had ALA-accredited master's degrees, none had unaccredited library master's degrees, 13 (56.5%) had second master's degrees, 1 (4.3%) had a Ph.D., and 2 (8.7%) had an other professional degree. (Source)