March 16, 2018

LJ Index 2015: E-Circ Not Ready for Prime Time

This 2015 edition of the LJ Index is its eighth. The Institute of Museum & Library Services’ (IMLS) recently released FY13 Public Library Survey (PLS) data set, on which the LJ Index is based, contains for the first time data on circulation of electronic materials—primarily downloadable ebooks and audio and video files. We had hoped to be able to incorporate this new data into the LJ Index design this year, but that was not possible for several reasons. That change must be put off one more year.

As the key obstacle, nonreports will be greatly diminished in the next data release (FY14 data in 2016), and we expect to make that change next time around.

E-circulation: subset or new data?

One of the issues with the new circulation of e-materials data element is the clarity of the concept itself. Between them, the long-standing definition of total circulation and the new definition for circulation of electronic materials leave one wondering whether this new data element is a subset of total circulation or a new data element, counting a (relatively) new type of activity for the first time. The answer to this question remains unclear. Nineteen (19) libraries reported e-circulation equivalent to 50 percent of their total circulation, and 81 libraries reported e-circulation equal to or in excess of 25 percent of their total circulation. Trailblazers? Perhaps. But one cannot help wondering how clear the relationship between total circulation and e-circulation is to local reporters of library statistics. For the 4,703 libraries reporting something greater than zero for e-circulation, the median for e-circulation as a percentage of total circulation is only three percent.

Given the changing nature of library use, the uncertainty about the relationship between total circulation and e-circulation raises more questions about just how “total” total circulation is. While the long-standing definition of total circulation explicitly says “all library materials of all types,” its note also says, “Count all materials in all formats that are charged out for use outside the library.” Historically, this long-unchanged definition was not interpreted to include nonphysical information sources, and the phrase “charged out for use outside the library” seems to convey an at least implied assumption that the circulating materials being counted are physical materials housed in the library until they are borrowed. That said, it is also interesting to note what at least implicitly isn’t included in e-circulation. The definition of the new data element seems to be clear in limiting this new count to downloadable materials (ebooks, audio, and video files); thus, streaming media—the latest cutting edge in collection development—appear to be excluded. Database use is explicitly excluded.

Lagging states and other nonreports

The Public Library Survey (PLS) is a partnership between IMLS and the state library agencies. The latter conduct the surveys that generate the data. Historically, for this reason, there have always been states for which the annual public library data are as much as a year older than for most other states. So we were disappointed, though not surprised, to find that ten states had not yet had the opportunity to ask their libraries to report this important new data element. Consequently, a full 20 percent of the nation’s libraries did not have the opportunity to report e-circulation this time around. We were unwilling to redesign the LJ Index and Star Library format until there is greater reporting of these measures by a larger proportion of the nation’s libraries.

ljx151101webStarLibsEcircTbl1E-circ outliers

Lagging states were not the only issue with the new e-circulation statistic. When we examined the available e-circulation data for each spending peer group, we found many concerning outliers. As noted earlier, all outliers are not necessarily incorrect figures. Sometimes, especially with per capita statistics, there are known forces at work in the way a public library is organized that may give it an “edge” in the LJ Index calculations and explain satisfactorily large figures that would otherwise appear implausible.

As e-circulation is a new data element, new edit checks associated with it need to be developed for use by local, state, and federal personnel as they scrutinize reported figures. Two such needed checks seem especially obvious to us. First, libraries should be asked to confirm their e-circulation figures, if e-circulation is beyond a certain proportion of total circulation. In this case, 50 percent seems a lax standard to us.

Second, local confirmation should be sought whenever e-circulation per capita far exceeds national norms. For this year’s Star Libraries, circulation of e-materials per capita averaged 2.76, but its median for this group was only 1.47. (For all LJ Index institutions, e-circulation per capita averaged 0.32, and had a median of 0.16. These norms, however, are seriously impacted by reported zeroes, which we will take up shortly.) Based on the top five reports for each expenditure range, it is probably advisable to ask local library representatives to explain or reconsider—and perhaps revise—their e-circulation figures when they reach double digits, as such high figures were reported this first time only in exceedingly rare cases. If such figures do not require revision, they may indicate extraordinary levels of e-circulation activity or, perhaps, simply a continuation of the kind of outliers sometimes seen legitimately for the other four LJ Index statistics. Most of the time, discrepancies between legal service area populations—the basis for per capita statistics—and actual populations served explain extraordinarily high outliers.

ljx151101webStarLibsEcircTbl2Reported zeroes

At the other extreme from high outliers are reported zeroes. Considering what a relatively new service allowing borrowers to download ebooks, audio, and video files is for many public libraries, it is not surprising that about one out of seven libraries reported zero for such transactions as late as FY13. Not surprisingly, zeroes were more likely to be reported as library expenditures decreased. While no libraries spending $5 million or more annually reported zero for e-circulation, more than one-third of those spending $10,000–$49,999 and more than one-fifth of those spending $50,000–$99,999 reported zero for e-circulation. Substantial numbers of libraries likely to be located in rural areas and less likely to have MLS-degreed librarians have not yet ventured into this new realm of service or are just beginning to at this writing.

Forthcoming data

Despite our disappointment that e-circulation could not be incorporated into the LJ Index this year, we expect it will happen next year. And there are at least two more new output measures in the pipeline: Wi-Fi access usage and visits to library websites. In the meantime, read on for more about this year’s more-competitive-than-ever crop of America’s Star Libraries.


Total Circulation:
The total annual circulation of all library materials of all types, including renewals.

Note: Count all materials in all formats that are charged out for use outside the library. Interlibrary loan transactions included are only items borrowed for users. Do not include items checked out to another library.

Circulation of Electronic Materials*:
The total annual circulation of all electronic materials.

Electronic Materials are materials that are distributed digitally and can be accessed via a computer, the Internet, or a portable device such as an ebook reader.


» Next page: “Understanding Star Status Shifts”

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Keith Curry Lance & Ray Lyons About Keith Curry Lance & Ray Lyons

Keith Curry Lance ( is an independent consultant based in suburban Denver. He also consults with the Colorado-based RSL Research Group. In both capacities, he conducts research on libraries of all types for state library agencies, state library associations, and other library-related organizations. For more information, visit
Ray Lyons ( is an independent consultant and statistical programmer in Cleveland. His articles on library statistics and assessment have also appeared in Public Library Quarterly, Public Libraries, and Evidence Based Library and Information Practice. He blogs on library statistics and assessment at

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