Analytics

Click the links below to access and download one of our most popular resources, the ARL Investment Index, commonly referred to as the "ARL Ranking":

Library Investment Index [xls]

Chronicle of Higher Education Publication of the Index

The current ARL statistics include data on collections, staffing, expenditures, library services, and library and university characteristics for the ARL university libraries.

This site will allow you to:

  • review the library data collected by ARL
  • generate rankings of institutions by selected criteria
  • create graphs from the data
  • generate summary statistics for all ARL libraries
  • download the data by year in spreadsheet format
  • review the ARL index and membership criteria
Accessing Analytics

The full Analytics menu is available to individuals with active accounts. Click here to access Analytics. If you do not have an account, please click here.

History

Statistics have been collected and issued annually for the members of the Association of Research Libraries since 1961-62. Before that, annual statistics for university libraries had been collected by James Gerould, first at Minnesota and later at Princeton. These data cover the years 1907-08 through 1961-62, and are now called the Gerould statistics. The whole data series from 1908 to the present represents the oldest continuing library statistical series in North America. The current ARL statistics include data on collections, staffing, expenditures, library services, and library and university characteristics.

The Gerould Statistics are now available in a revised edition here.

A Guide to the Machine-Readable Version of the ARL Statistics is on the ARL site.

Starting in 2005–06, ARL is calculating a Library Investment Index (previously named Expenditures-Focused Index and now commonly referred to as "the ARL Raking") as an alternative to the historical index known as the ARL Membership Criteria Index. The Library Investment Index replaces the public availability of the ARL Membership Criteria Index and is retroactively calculated for the 2002-03 to 2005-06 data. The Library Investment Index is highly correlated with the Membership Criteria Index and less affected by changes in the collections variables. The methodology behind this new index is described by Bruce Thompson in his October 2006 paper, "Some Alternative Quantitative Library Activity Descriptions/Statistics that Supplement the ARL Logarithmic Index."

The principles and procedures for academic library membership in ARL are based partly on quantitative data that provide a view of the range of resources deployed among the existing members of the Association. However, the ARL Index does not attempt to measure a library's services, quality of collections, or success in meeting the needs of users. Rather, it is a summary measure of relative size among the university library members of the Association.

The ARL Library Investment Index calculates principal component scores and the analysis is based on all university member libraries' data. The variables used in the Index were determined by factor analysis. These variables are:
Total Library Expenditures (totexp)
Salaries & Wages Professional Staff (salprf)
Total Library Materials Expenditures (explm)
Professional plus Support Staff (totstf)

The ARL Library Investment Index Index was proposed as an alternative index by Bruce Thompson, Distinguished Professor of Educational Psychology and CEHD Distinguished Research Fellow, and Distinguished Professor of Library Science, Texas A&M University, and Adjunct Professor of Family and Community Medicine, Baylor College of Medicine (Houston). It was incorporated into the recommendations of the Task Force on New Ways of Measuring Collections, chaired by Brinley Franklin (University of Connecticut) and approved by the ARL Board in February 2007. A presentation on these changes was made by Colleen Cook (Texas A&M), Chair, Statistics and Assessment Committee, at the May Membership meeting in St. Louis in 2007. It replaces the public availability of the historical Membership Criteria Index. A detailed description of the historical Membership Criteria Index is available in The ARL Library Index and Quantitative Relationships in the ARL, by Kendon Stubbs (Washington, DC: ARL, 1980).

Although similar to the ARL Membership Criteria Index in reflecting the investments made in research libraries, the ARL Library Investment Index is less affected by the electronic availability of content and, as a result, by the rapidly changing context of library collections. Collections and content is made available in many new ways to library users and ARL’s historical descriptive statistics are being re-examined and adjusted to reflect the changing context of collection access and ownership. The ARL Statistics and Assessment Committee is engaged in defining additional variables and is developing new quantitative and qualitative indicators and indices to describe research library collections and services and their contribution to research, teaching and learning.

For additional details and background on the development of the ARL Library Investment Index, see:

Bruce Thompson, ‘Some Alternative Quantitative Library Activity Descriptions/Statistics that Supplement the ARL Logarithmic Index,’ October 6, 2006. See: http://www.arlstatistics.org/documents/admin/2012/Thompson_2006_Some Alternative Quantitative Library Activity Descriptions.pdf

Brinley Franlin, Colleen Cook, Martha Kyrillidou and Bruce Thompson. Library Investment Index-Why Is It Important? Proceedings of the 2008 Library Assessment Conference: Building Effective, Sustainable and Practical Assessment, August 4-7, 2008, Seattle, Washington (Washington DC: Association of Research Libraries, 2009): 147-154. See: http://www.arlstatistics.org/documents/admin/Franklin_etal_ 2008_Library Investment Index why is it important.pdf

This section is based on the four variables used to determine the ARL investment index scores for each institution (total professional plus support staff, total materials expenditures, professional salaries & wages, and total library expenditures), and the ARL investment index score. Use this part of the site to create a report displaying all of these variables for individual institutions (2003 forward); to display a ranked report of any one of the five variables for any number of institutions for a single year; to produce a graph of the variables for one institution from 2003 to the current year; or to graph one variable for up to nine institutions. Visit the ARL site for more information on the Library Investment Index.

Data of Individual Libraries

Select one library to display the following variables from 2003 forward: total professional plus support staff, total materials expenditures, professional salaries & wages, total library expenditures, ARL investment index score, and rank in ARL investment index. (Note: Institutions which entered the ARL during this period have data for only some years.)

Institutions

ARL Investment Index Data

To produce a report of all Library Investment data for individual years from 2003 onward, select a year, an index variable, and any number of institutions. To make multiple selections, hold down the control key while clicking on your choices.

To find the ARL Investment Index Ranking, use the Ranked Lists section and choose the ARL Investment Index Rank variable and sort ascending.

Index Variable Institutions
Year

Graphs of Individual Library Data

Select one library at a time for graphs of the following variables: total professional plus support staff, total materials expenditures, professional salaries & wages, total library expenditures, ARL investment index score, and rank in ARL investment index. (Note: Institutions which entered the ARL during this period have data for only some years.)

Institutions

Graphs of Multiple Libraries

Select one of the following variables to be graphed. Then select up to nine libraries for individual graphs by holding down the control key and clicking on library names. To see multiple libraries on the same graph, go the the Graphs tab and choose the "Multiple Institutions, One Variable" option at the bottom of the page.

Variables Institutions
Four-Variable Formulas for ARL Investment Index Scores
Formula for ARL Statistics 2012-13
0.000000051136906 x total library expenditures
+ 0.00000001441152 x salaries & wages professional staff
+ 0.000000019076823 x total library materials expenditures
+ 0.00000000000036 x professional plus support staff
- 1.845714
Formula for ARL Statistics 2011-12
0.000000051366896 x total library expenditures
+ 0.000000015524539 x salaries & wages professional staff
+ 0.00000001920517 x total library materials expenditures
+ 0 x professional plus support staff
- 1.812411
Formula for ARL Statistics 2010-11
0.000000056261178 x total library expenditures
+ 0.000000016718432 x salaries & wages professional staff
+ 0.000000018421743 x total library materials expenditures
+ 0.000000000000439 x professional plus support staff
- 1.91696034328239
Formula for ARL Statistics 2009-10
0.000000055601829 x total library expenditures
+ 0.000000016940516 x salaries & wages professional staff
+ 0.000000018370288 x total library materials expenditures
+ 0.000000000000441 x professional plus support staff
- 1.85706161530459
Formula for ARL Statistics 2008-09
0.000000053606745 x total library expenditures
+ 0.00000001591896 x salaries & wages professional staff
+ 0.00000001769161 x total library materials expenditures
+ 0.000000000000452 x professional plus support staff
- 1.78909748139108
Formula for ARL Statistics 2007-08
0.000000055218891 x total library expenditures
+ 0.000000016036748 x salaries & wages professional staff
+ 0.000000017562588 x total library materials expenditures
+ 0.000000000000483 x professional plus support staff
- 1.83086947737619
Formula for ARL Statistics 2006-07
0.000000058589685 x total library expenditures
+ 0.000000017428985 x salaries & wages professional staff
+ 0.000000018531841 x total library materials expenditures
+ 0.000000000000551 x professional plus support staff
- 1.84298864816635
Formula for ARL Statistics 2005-06
0.00000006119392 x total library expenditures
+ 0.000000018067142 x salaries & wages professional staff
+ 0.000000019127712 x total library materials expenditures
+ 0.000000000000589 x professional plus support staff
- 1.83952070681504
Formula for ARL Statistics 2004-05
0.00000006606022 x total library expenditures
+ 0.000000019130472 x salaries & wages professional staff
+ 0.000000019770204 x total library materials expenditures
+ 0.000000000000648 x professional plus support staff
- 1.84611277143992
Formula for ARL Statistics 2003-04
0.000000067864816 x total library expenditures
+ 0.00000001971782 x salaries & wages professional staff
+ 0.000000020437451 x total library materials expenditures
+ 0.000000000000696 x professional plus support staff
- 1.83414315800814
Formula for ARL Statistics 2002-03
0.000000070617137 x total library expenditures
+ 0.000000019425091 x salaries & wages professional staff
+ 0.000000020811188 x total library materials expenditures
+ 0.000000000000758 x professional plus support staff
- 1.81275170706434