Wednesday, July 6, 2011

PL 24/11: Size matters

Filed under: IFLA, statistics — Tags: — plinius @ 9:14 pm

Google Docs has good tools for visualizing library statistics.

Norway has about 400 municipalities, each with its separate public library system. Municipal autonomy is a big thing in my country.

This spring I have done a small statistical study of the 2009 public library statistics in KOSTRA. I did the following:

  • retrieved the 400 values for each of fifteen library variables from the KOSTRA data base
  • stored them in a Google Docs spreadsheet
  • grouped the libraries into five size groups
  • calculated the values of twenty different indicators
  • calculated the three quartiles (Q1, median, Q3) for each indicator
  • created twenty line diagrams that show the quartile values for each size group
  • published the spreadsheet

The graphics can be inspected here.

Below I add some brief comments on each indicator.

  1. Visits per capita increases substantially, from about 3.5 to about 5.5, when we go from the smallest to the largest municipalities.
  2. The variability (dispersion) of the visits, as measured by the quartile difference, is much greater in smaller than in bigger libraries.
  3. Loans per capita follow a shallow U-curve. The loans per capita value is lowest in the 10-20 thousand range and increases both when we go higher up and when we go lower down. The 50.000 plus group outperforms the less than 5 group, however.
  4. The activity level is the sum of visits and loans. These values are about 8.5 in small libraries (up to ten thousand inhabitants), almost 10 in the 20-50.000 range and about 12 in the 50.000+ group.
  5. The activity dispersion is high in the two smallest group and substantially lower in the three largest groups.
  6. The staff density and the operational costs per capita are much higher in smaller than in larger municipalities.
  7. The dispersion of these indicators is very high at the lower end.
  8. Productivity increases substantially as we go from small to large libraries. The increase seems to taper off at the high end, however.
  9. Salary levels are almost the same regardless of size. There is only a small increase as we move from small to big libraries.
  10. The average media cost per accression increases by more than fifty percent as we go from the smallest to the largest libraries. The reason is obvious: free books from The Cultural Fund are relatively more important in smaller than in larger libraries.
  11. The media costs as a percentage of the total operational budget moves in the opposite direction, however: from eighteen percent in the smallest to twelve percent in the largest libraries.
  12. The three turnover rates, for non-fiction, fiction and children’s books respectively, improve drastically as we move from small to large libraries. Turnover rates in the biggest municipalities are about three times as high as the rates in the smallest units.
  13. Smaller libraries are generally more focused on loans than on visits. The number of loans per visit goes down by about forty percent when we go from the smallest to the largest municipality.
  14. The number of non-book and non-fiction loans per user is much higher in large than in small muncipalities.
  15. The number of fiction loans and of children’s loans per user is highest in small libraries, however.
  16. Non-book media account for about 23 percent of all loans in the smallest, and for about 34 percent in the largest communities.
  17. In the smallest communities, non-fiction constitutes about 30 percent of the book lending to adults.
  18. In communities with more than ten thousand inhabitants the share is above 45 percent
  19. Children’s books accounts for 45 percent of all book loans.




  1. Hello Tord (Plinius)

    How intriguing! I would love to explore this difference between Norway and U.S. statistics further sometime.

    As my recent blog reports (, we see the opposite pattern in U.S. libraries. A few years ago I looked at this by aggregating longitudinal data (1999 – 2004). Here are links to charts of visits per capita ( and circulation (loans) per capita ( Mean and median values for the different sized libraries are not too divergent. However, the tiniest libraries consistently surpass the others on these measures.

    Comment by raylyons — Thursday, July 7, 2011 @ 6:12 pm

  2. […] I made the claim a couple of things made me wonder more about it. First, Tord Høivik found quite opposite trends based on Norwegian public library statistics he analyzed from the KOSTRA municipal-county reporting […]

    Pingback by Library Science | Lib(rary) Performance — Thursday, September 29, 2011 @ 7:40 pm

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