The EveryLibrary Institute is working with the Syracuse University School of Information Studies to establish an open-access interactive online platform that increases understanding of return on investment of public libraries. Here is prototype library funding and return on investment map, it is based data provided by the Institute of Museum and Library Services for the 2016 data collection. [In Louisiana that is the 2016 calendar year for most libraries.] In this interactive map, you can find your library and view your library's preliminary return-on-investment (ROI) indicator. This ROI indicator is based on early data and is displayed only for informative purposes.
ALA (American Library Association) has a section of its web site called "Libraries Matter" [http://www.ala.org/tools/research/librariesmatter/] there are separate sections for:
There is an older (2016) Public Libraries Online article "Demonstrating the Library’s ROI" by Paula Wilson which has a narrative discussion on the uses of ROI for library advocacy. http://publiclibrariesonline.org/2016/07/demonstrating-the-librarys-roi/
Colorado Research Service: https://www.lrs.org/data-tools/public-libraries/return-on-investment/
This is one of the most complete and up-to-date compilations of the various ROI studies done. It includes a focus on Colorado public libraries. The calculator formerly developed had been based on data from 2008. They recommend using more up-to-date data, such as the Texas study (below).
Texas State Library: https://www.tsl.texas.gov/roi
This is a state-wide study done in 2017.
Summary of Recent Public Library Return on Investment Studies (CO page): https://www.lrs.org/data-tools/public-libraries/return-on-investment/recent-studies/
There are extensive notes for each of these studies as well as a list of out of state studies in a table format.
IFLA (The International Federation of Library Associations): https://www.ifla.org/node/93197
IFLA published a report in July 2020 which reviewed 10 years worth of Return on Investment (ROI) studies. The link above is to the announcement and an abstract of the report. The full report is available here: https://www.ifla.org/files/assets/hq/library_roi.pdf
The Ohio Library Council (OLC) publishes a calculator which a library can use to determine the value of services any individual receives. The current calculator uses cost data from 2017: https://libraryfunding.olc.org/libraries/roi-calculator/
The National Library of Medicine (part of the National Institutes of Health [NIH]) offers two calculators:
Cost Benefit and ROI Calculator: https://nnlm.gov/mcr/training/program-evaluation/cost-benefit-and-roi-calculator
Valuing Library Services Calculator: https://nnlm.gov/mcr/training/program-evaluation/calculator
A number of sites use a simple calculator which was initially used by the Massachusetts Library Association and Chelmsford (MA) Public Library by someone who worked there. The values for that calculator can be found on a blog Swiss Army Librarian [please note that the data is old]. The ALA version of this calculator is still on their web site.