**2020 Library Assessment Conference**

Wednesday, February 18, 2021

1:15 p.m. and 4:35 p.m. eastern time

https://laconf2020.exordo.com/programme/presentation/61

The purpose of this paper is to explain an advanced version of Cost Per Use, called Net Cost per Paid Use (NCPPU), which values citations and authorships as types of use, excludes papers that can be obtained for free, and incorporates the cost of ILL.

Net Cost Per Paid Use is calculated by taking the subscription cost and subtracting the anticipated ILL cost, and dividing this by the usage (measured by number of downloads plus weighted authorships and citations) that is not available for free via Open Access or Perpetual access backfile. Some of these terms involve complicated calculation (anticipated ILL cost, the proportion of usages available for free), which will be explored in the paper.

We graph NCPPU against traditional Cost Per Use to show examples where collections decisions made with traditional cost per use would over- or under-value journals, given their ILL costs, Open Access proportion, and/or authorship interest for a given university.