Data Archive Introduction | PLDF3

State Summary/State Characteristics Longitudinal Data File (PUSUM)

Robert E. Molyneux


This page documents a longitudinal set of state summary public library data constructed from two sources. One is the annual Public Library Survey formerly collected by the National Center for Education Statistics (NCES) under the Federal State Cooperative System (FSCS) program and more recently from the continuing series published by the Institute of Museum and Library services through the Public Libraries Survey. This compilation is of the State Summary/State Characteristics Data File, that is Public Use Summary (hence, I conclude, PUSUM which convention NCES and IMLS have named files in this series). The dataset now contains 1,560 observations (an observation being summary data from the libraries in one state for one year), with 85 variables per observation, although not all variables were collected all years. These data are from the states, the District of Columbia, and occasionally outlying territories.

The summary data were originally compiled starting in Fiscal Year (FY) 1987. For reasons discussed shortly, the set of data discussed here only have the data from FY 1992-FY 2020 or 29 years. The data are available in formats discussed at the bottom of the page at Distribution and Formats.

The state summary data are fundamentally different from the Public Library Data File which is a compilation of data from over 10,000 public libraries collected from FY 1987-FY 2020. While PLDF3 is designed to have only unimputed data from all the public libraries, PUSUM includes imputed data.

These summary data are the result of analyzing aspects of those data and other data. Given that not all libraries respond to all survey items, NCES and IMLS have used imputation techniques to compensate for those missing data. Documentation is carried in the various sources cited in the list of NCES and IMLS Public Library Survey documentation elsewhere on this site. PUSUM contains imputed data given that it is attempting to compensate for the missing values for purposes of arriving at national assessments of the state of public libraries.

Knowing these facts, could you replicate these summary data using the Public Library Data File either in its unimputed or imputed forms? Probably not. The documentation on how the imputations were done is improving but does involve data that are masked in the Public Library Data file for privacy reasons. NCES and IMLS have published “unrestricted” and “restricted”data. Data are suppressed in the restricted data. For example, in smaller libraries salary information when the staff is sufficiently small to cause a privacy concern. All the PLDF3 data are from the restricted data.

IMLS has access to data suppressed for individual libraries. Data are suppressed in smaller libraries, for instance, salary information when the staff is sufficiently small to cause a privacy concern. Of course, you could do your own imputations. More telling, though, is the fact that these summary files are also constructed using the Restricted Use data, in part. These Restricted Use data are not available for public use. The great value of PUSUM is assessing the state of public libraries in the U.S. on national and state-levels. Without imputations, there are very few data in this series so I compile them with the imputations. For a universe survey attempting to give the state of the nation's libraries, this is the series to use.

A further complication follows from this practice of imputation. The documentation for years (here 2018) has specifically warned in the much same language:

Comparisons to estimates prior to FY 1992 should be made with caution, as earlier estimates do not include imputations for nonresponse and the percentage of libraries responding to a given item varied widely among states. (p. 6)

According to the documentation from earlier years, there are supposed to be summary data from FY 1987-FY 1991. 1991 is made up of a summary from the reporting libraries so that comparing FY 1991 with FY 1992 is likely to show discontinuities that are an artifact of the imputations themselves and not from any change in the characteristics of those libraries. For FY 1987-FY 1989, in spite of the documentation's saying there are summary data, they are sketchy. FY 1987 has a few variables reported for the 19 states' summaries. Summary data for FY 1988 were not with the rest of the FY 1988 data and I don't know where they are. FY 1989 does have summary data in a separate file as does FY 1990. All imputations could be taken out of the post-1992 data but experimenting with that idea resulted in derivative datasets with very few values. So, we get some data imputed by methods that are becoming clearer but still not unambiguous or we get vanishingly few data.


The tables below list the variables that were dealt with in constructing PUSUM. The intent was to group all like variables in the various years in one variable name. Rarely was there any ambiguity in reading the documentation from year to year.

Two variables have been added to each year's data in order to ease processing: state and year. (NCES/IMLS variables are in upper case while any non-NCES/IMLS variables are in italics. year was hard coded in one of the programs and is the nominal year of reporting and the same as the fiscal year that appears on publications. The NCES/IMLS library data have been issued as annual publications without explicit acknowledgement in the data of previous years or years that might follow although an infrastructure which allows this practice has improved steadily over the years. For PUSUM, creation of a longitudinal file is relatively straightforward. State is the two-digit postal code. This variable was made from various variables in the dataset as noted below. For recent years, it has been derived from STABR.

A spreadsheet in three formats (pusumvariables.ods, pusumvariables.xlsx, and pusumvariables.csv) presents these variables in a more portable format for the duration of the series.

The following tables have details on the variables in PUSUM. The convention followed is to use the variable name from the current documentation except where the data are no longer collected and the short definitions and notes come, largely, from the current documentation. The variable names have been static for some years.. The wording differs on occasion for variables documented in the earlier years but the definitions overall are pretty consistent. Imputation flags listed in the documentation in Appendix G are not included in this list nor in PUSUM.

As a general rule, the improvements over time in this series and PLDF3 are notable and commendable but, of course, they started from a high level. Both of these series have excellent documentation so anyone using them owes thanks to many people.

Identification Variables
Variable Short definition Years History Notes
state Two-letter State Code ALL Created from STABR Used for processing.
year Year of data collection ALL Inserted by code Used for processing.
STABR Two-letter American National Standards Institute (ANSI) State Code ALL STABR (1992-) See PUB_FIPS, below.
Population Variables
Variable Short definition Years History Notes
POPU_LSA Population of the Legal Service Area ALL POPU (1992-97)
POPU_LSA (1998-)
POPU_UND Unduplicated population of the legal service
area for the library (constructed variable).
ALL PERIOD_POP (1992-1997)
POPU_UND (1998-)
REGBOR Registered Borrowers 2006- REGBOR (2006-  
POPU_ST Official state population estimate ALL PERIOD_EST (1992-1997)
POPU_ST (1998-)
Service Outlets
Variable Short definition Years History Notes
CENTLIB Number of central libraries ALL CENTLIB (1992-)  
BRANLIB Number of branch libraries ALL BRANLIB (1992-)  
BKMOB Number of bookmobiles ALL BKMOB (1992-)  
Full-Time Equivalent (FTE) Paid Staff
Variable Short definition Years History Notes
MASTER ALA-MLS Librarians ALL MASTER (1992-)  
LIBRARIA Total number of FTE employees holding the title of librarian. ALL LIBRARIAN (1992-97)
LIBRARIA (1998-)
OTHPAID All other paid FTE employees. ALL OTHPAID (1992-)  
TOTSTAFF Total paid FTE employees ALL TOTEMP (1992-97)
TOTSTAFF (1998-)
Operating Income
Variable Short definition Years History Notes
LOCGVT Operating income from local government ALL LOCGVT (1992-)  
STGVT Operating income from state government ALL STGVT (1992-)  
FEDGVT Operating income from federal government ALL FEDGVT (1992-)  
OTHINCM Other operating income (i.e., income not included in LOCGVT, STGVT, and FEDGVT) ALL OTHINCM (1992-)  
TOTINCM Total income (Sum of LOCGVT, STGVT, FEDGVT, and OTHINCM) ALL TOTINCM (1992-)  
Operating Expenditures
Variable Short definition Years History Notes
SALARIES Salaries and wages for all library staff ALL SALARIES (1992-)  
BENEFIT Employee benefits for all library staff ALL BENEFIT (1992-)  
STAFFEXP Total staff expenditures (SALARIES plus BENEFIT) ALL TOTEXP (1992-97)
STAFFEXP (1998-)
PRMATEXP Operating expenditures for print materials (including books, serial back files, current serial subscriptions, government documents) 2003- PRMATEXP (2003-)  
ELMATEXP Operating expenditures for library materials in electronic format 1995- ELMATEXP (1995-)  
OTHMATEX Operating expenditures for all other library materials (microform, audio, video, DVD, and new formats) 2003- OTHMATEX (2003-)  
TOTEXPCO Total expenditures on library collections. ALL TOTEXPCOL (1992-97)
TOTEXPCO (1998-)
OTHOPEXP Other operating expenditures (i.e., expenditures not included in STAFFEXP and TOTEXPCO) ALL OTHOPEXP (1992-)  
TOTOPEXP Total operating expenditures (Sum of STAFFEXP, TOTEXPCO, and OTHOPEXP) ALL TOTOEXP1 (1992-97)
TOTOPEXP (1998-)
Capital Expenditures
Variable Short definition Years History Notes
CAPITAL Expenditures for capital outlay ALL CAPITAL (1992-)  
Capital Revenue
Variable Short definition Years History Notes
CAP_REV Capital revenue for major capital expenditures 2003- CAP_REV (2003-)  
FCAP_REV Federal government capital revenue 2005- FCAP_REV (2005-)  
LCAP_REV Local government capital revenue 2005- LCAP_REV (2005-)  
OCAP_REV Other capital revenue 2005- OCAP_REV (2005-)  
SCAP_REV State government capital revenue 2005- SCAP_REV (2005-)  
Library Collections
Variable Short definition Years History Notes
BKVOL Number of books and serial volumes ALL BKVOL (1992-)  
EBOOK Electronic books (E-books) (digital documents, including non-serial government documents in digital format) 2003- EBOOK (2003-)  
AUDIO Number of audio materials 1992-2009 AUDIO (1992-2009) No longer collected.
AUDIO_DL Audio - downloadable titles 2010- AUDIO_DL (2010-)  
AUDIO_PH Audio - physical units 2010- AUDIO_PH (2010-)  
VIDEO Number of video materials 1992-2009 VIDEO (1992-2009) No longer collected.
VIDEO_DL Video - downloadable titles 2010- VIDEO_DL (2010-)  
VIDEO_PH Video - physical units 2010- VIDEO_DL (2010-)  
DB_LOC Locally licensed databases 2006-2010 DB_OTH (2006-2010) No longer collected.
DB_LO_OT Local/Other cooperative agreements 2012- DB_ST (2006-2015) No longer collected.
DB_ST State licensed databases 2006-2015 DB_ST (2006-2015) No longer collected.
DB_OTH Other licensed databases 2006-2015 DB_ST (2006-2015) No longer collected.
DATABASE Databases (locally mounted or remote, full-text or not, for which temporary or permanent access rights have been acquired) 2003-2015 DATABASE (2003-) No longer collected.
SUBSCRIP Number of current serial subscriptions ALL SUBSCRIPT (1992-97)
SUBSCRIP (1998-)
ESUBSCRP Current electronic serial subscriptions 2003-2009 ESUBSCRP (2003-2009) No longer collected.
EC_LO_OT Local/Other electronic collections 2015- EC_LO_OT (2015-)  
EC_ST State electronic collections 2015- EC_ST (2015-)  
ELECCOLL Total electronic collections 2015- ELECCOLL (2015-)  
Public Service Hours
Variable Short definition Years History Notes
HRS_OPEN Total annual public service hours for all service outlets ALL DUPLI (1992-97) HRS_OPEN (1998-)  
Variable Short definition Years History Notes
TOTCIR Total annual circulation transactions ALL TOTCIR (1992-)  
TOTCOLL Total annual circulation transactions 2016- TOTCOLL (2016-) Total annual count of physical item circulation, circulation of electronic material and successful retrieval of electronic information
KIDCIRCL Total annual circulation (including renewals) of all children's materials in all formats to all users ALL KIDCIRCL (1992-)  
ELMATCIR Circulation of electronic materials 2013- ELMATCIR (2013-)  
PHYSCIR Physical item circulation 2016- PHYSCIR(2016-) The annual circulation of all physical library materials of all types, including renewals.
ELCONT Electronic content use 2016- ELCONT (2016-) The number of full-content units or descriptive records examined, downloaded, or otherwise supplied to user, from online library resources that require user authentication but do not have a circulation period.
ELINFO Successful retrieval of electronic information 2016- ELINFO (2016-) The number of full-content units or descriptive records examined, downloaded, or otherwise supplied to user, from online library resources that require user authentication but do not have a circulation period.
Inter-Library Loans
Variable Short definition Years History Notes
LOANTO Total annual loans provided to other libraries ALL LOANTO (1992-)  
LOANFM Total annual loans received from other libraries ALL LOANFM (1992-)  
Library Services
Variable Short definition Years History Notes
VISITS Total annual library visits ALL ATTEND (1992-1997)
VISITS (1998-)
ATTEND was defined as "Annual attendance in library" which, I understand, is regarded as the same as VISITS today.
No longer collected.
WEBVISIT Total visits (sessions) to library website 2018- WEBVISIT (2018-  
WIFISESS Total annual wireless sessions 2014- WIFISESS (2014-  
REFERENC Total annual reference transactions ALL REFERENCE (1992-1997)
REFERENC (1998-)
TOTATTEN Total annual attendance at all library programs. 2004- TOTATTEN (2004-)  
KIDATTEN Total annual attendance at all programs intended primarily for children. Includes adults who attend programs intended primarily for children. ALL KIDATTEN (1992-)  
YAATTEN Total audience at all young adult programs. 2009- YAATTEN (2009-)  
TOTPRO Total library programs. 2004- TOTPRO (2004-)  
KIDPRO Total children's programs. 2005- KIDPRO (2005-)  
YAPRO Total young adult programs. 2009- YAPRO (2009-)  

Electronic Technology
Variable Short definition Years History Notes
ELACCEXP Operating expenditures for electronic access 1995-2002 ELACCEXP (1995-2002) No longer collected.
ELMATS Number of library materials in electronic format 1995-2002 ELMATS (1995-2002) No longer collected.
STFTERMS Internet terminals used by staff only 1998-2002 STFTERMS (1998-2002) No longer collected.
GPTERMS Internet terminals used by general public 1998- GPTERMS (1998-)  
ERES_USR Users of electronic resources per typical week 1999-2005 ERES_USR (1999-2005) No longer collected.
PITUSR Users of public Internet terminals per year 2006- PITUSR (2006)  

Variable Short definition Years History Notes
STARTDAT Reporting period start date ALL PERIOD_PSM (1992-1997)
STARTDAT (1998-)
Month/year format, for example: "07/2003"
No longer collected.
ENDDAT Reporting period end date ALL PERIOD_PEM (1992-1997)
ENDDAT (1998-)
Month/year format, for example: "06/2003"
No longer collected.
FIPSST Two-digit FIPS State Code. 2009-2014 PUB_FIPS (1992-2008) This is a alphabetic code (Alabama = AL). STABR uses a character state code (Alabama = AL).;
No longer collected.
PUB_FIPS Two-digit FIPS State Code. 1992-2008 PUB_FIPS (1992-2008) This is a numerical code (Alabama = 01). STABR uses a character state code (Alabama = AL).;
No longer collected.
YR_SUB FSCS submission year of public library data in four-digit format (YYYY) ALL YR (1992-97) + 1900
YR_SUB (1998-)
YR is a two-digit year format and YR_SUB is four digits.
OBEREG Bureau of Economic Analysis Code ALL OBEREG (1992-) 00–U.S. Service Schools
01–New England (CT ME MA NH RI VT)
02–Mid East (DE DC MD NJ NY PA)
03–Great Lakes (IL IN MI OH WI)
04–Plains (IA KS MN MO NE ND SD)
05–Southeast (AL AR FL GA KY LA MS NC SC TN VA WV)
06–Southwest (AZ NM OK TX)
07–Rocky Mountains (CO ID MT UT WY)
08–Far West (AK CA HI NV OR WA)
09–Outlying Areas (AS FM GU MH MP PR PW VI)

Distribution and Formats

Format Filename Size
CSV pusum.csv 636 KB
LibreOffice Calc (ODF) pusum.ods 694 KB
Excel pusum.xlsx 601.6 KB

January 7, 2023