March 17, 2018

LJ Index 2012: Five-Year Reflection

When we first proposed the LJ Index ratings in 2008 we had several purposes in mind:

  • To showcase a substantial number of U.S. public libraries whose levels of service delivery distinguish them among their peers.
  • To rate libraries based on services delivered (outputs) only, exclusive of resources used (inputs).
  • To acknowledge the approximate nature of ratings of any kind by classifying the LJ Index awards into tiered 3-Star, 4-Star, and 5-Star categories.
  • To make the results understandable by using straightforward scoring methods and publishing the detailed data upon which rating scores are based, and to encourage libraries to explore these statistics regardless of whether they earned a Star or not.
  • To raise awareness of the need for improved completeness and accuracy of annual library statistical reporting.
  • To inspire discussion about new output measures that will reflect the changing nature of library service.

Given the current financial climate and evolving roles of 21st-century public libraries, we are more convinced of the relevance of these objectives than ever. Further information about the LJ Index design, calculation methods, qualifications for libraries to be included, and similar topics are available at

More libraries than ever (7,570) qualified for 2012 ratings (see second table, below). Since the first edition in 2009, the count of libraries rated has increased by 6.4 percent. In large part, this increase has been due to improved reporting of the four LJI per capita measures. In the spring 2009 edition, 919 libraries neglected to report one or more of the required output measures. However, this shrank to 477 this year—a 48 percent decrease in unreported data.

Four of the nine expenditure groups—$100K–$199K, $200K–$399K, $1M–$4.9M, and $10M–$29.9M—account for increases in the number of libraries rated in this 2012 edition. The other five groups had minor decreases in counts primarily owing to disqualifications for unreported data, service area populations dipping below 1000, or changes in expenditures that moved some libraries to different peer comparison groups. In the $30M+ group, for instance, expenditure decreases in 2010 caused three libraries to be reclassified into the $10M–$29.9M group.

Changes in mind

Speaking of year-to-year changes, it is important to be mindful of the potential volatility of annual ratings of any type, including ratings of libraries, colleges and universities, hospitals, and cities. In the LJ Index expenditure categories, new entrants in one group might make comparisons more or less competitive than in prior years. So, there can sometimes be a disconnect between an increase or decrease in a library’s data reported and its final LJI score. This is why it is essential to tread cautiously when interpreting a library’s LJI rating from one year to the next.

Readers may recall that, in any given edition of the ratings, each library’s output statistics are compared to the average (mean) values for those statistics in the expenditure group to which the library belongs. The more above-average a library’s data are, the higher the chances the library will earn a Star rating. The table below gives the mean values for the four LJI measures for this 2012 edition and the next gives library counts across the editions, while the third table gives mean LJI values for all five LJ editions.

Mean Values of LJ Index Measures November 2012 Ratings

Expenditure CategoryCirc Per Capita (Mean)Visits Per Capita (Mean)Program Attendance Per Capita (Mean)Pub Internet Computer Use Per Capita (Mean)
LJI Edition2012201220122012
IMLS Data Year2010201020102010
$30,000,000 +11.085.950.2621.32

US Public Libraries with LJ Index Scores by LJ Index and IMLS Data Year

Total Libraries Rated75707513740772687115
Expenditure CategoryLibrary Count
LJI Edition201220112010Fall 2009Spring 2009
IMLS Data Year20102009200820072006
$30,000,000 +4448453631

Mean Values of LJ Index Measures, All Five Editions

Expenditure CategoryCirc Per Capita (Mean)
LJI Edition201220112010Fall 2009Spring 2009
IMLS Data Year20102009200820072006
$30,000,000 +11.0810.9610.5198.51

Expenditure CategoryVisits Per Capita (Mean)
LJI Edition201220112010Fall 2009Spring 2009
IMLS Data Year20102009200820072006
$30,000,000 +5.956.045.845.285.12

Expenditure CategoryProgram Attendance per Capita (Mean)
LJI Edition201220112010Fall 2009Spring 2009
IMLS Data Year20102009200820072006
$30,000,000 +0.2620.2820.2880.2690.264

Expenditure CategoryPublic Internet Computer Use per Capita (Mean)
LJI Edition201220112010Fall 2009Spring 2009
IMLS Data Year20102009200820072006
$30,000,000 +1.321.331.321.591.18

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

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
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

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