ARL makes publicly available the ARL Library Investment Index (previously named the ARL Expenditures-Focused Index). Beginning with data for 2005-06, this Index replaces the public availability of the ARL Membership Criteria Index. This new Index is highly correlated with the ARL Membership Criteria Index and less affected by changes in the collections variables. The ARL Library Investment Index calculates principal component scores and the analysis is based on all university member libraries’ data (as compared with the ARL Membership Criteria Index, which is based on the 34 founding members of the Association). It is a summary measure of relative size among the university members of the association and has also been calculated retrospectively beginning with data from 2002-03. The Index scores are rounded to two decimal places, which may give the appearance of identical scores (and thus ranks) for some institutions; in fact, when the complete principal component score is calculated, it is extended to higher precision decimal places. Each institution has a unique result and place in the rank order.
Total Library Expenditures
Salaries & Wages Professional Staff
Total Library Materials Expenditures
Professional plus support staff