This indicator represents the relationship between the number of academic S&E publications and the amount of money expended for academic S&E R&D. Academic institutions include 2-year colleges, 4-year colleges or universities, medical schools, and university-affiliated research centers. This indicator is not an efficiency measure; it is affected by the highly variable costs of R&D and by publishing conventions in different fields and institutions. It may also reflect variations in field emphasis among states and institutions. Decreases in this indicator may be an effect of general price inflation as well as rising academic research costs. Publication counts are based on the number of articles that appear in a set of journals tracked by Elsevier’s Scopus database. The journal set consists of S&E publications (including publications on the natural sciences, the applied sciences, the medical sciences, and the social sciences but excluding the arts and humanities). Only documents published in referred scientific journals are counted (mostly articles, reviews, and conference proceedings), as these documents were reviewed by peers prior to being accepted for publication. The peer-review process is designed to ensure that the research is of good quality and constitutes an original contribution to scientific knowledge. Fractional counting at the level of researchers is used to ensure that a single paper is not counted several times. For example, if two of three authors are in state A and the third author is in state B, then two-thirds of the publication is attributed to state A, and one-third is attributed to state B.

Data on academic R&D are provided by the National Center for Science and Engineering Statistics and represent R&D at U.S. colleges and universities with over $150,000 in R&D expenditures.

The bibliometric data was revised in 2026 to reflect the data provider's updated methodology. For additional information, please see the Technical Notes.

Data source: Science-Metrix, special tabulations from Scopus; National Center for Science and Engineering Statistics, Higher Education Research and Development.