Are Online and Free Online Access Broadening or Narrowing Research?

[Stevan Harnad]

The decline in the concentration of citations, 1900-2007

Vincent Lariviere, Yves Gingras, Eric Archambault

http://arxiv.org/abs/0809.5250
(Deposited on 30 Sep 2008)

This paper challenges recent research (Evans, 2008) reporting that the
concentration of cited scientific literature increases with the online
availability of articles and journals. Using Thomson Reuters' Web of
Science, the present paper analyses changes in the concentration of
citations received (two- and five-year citation windows) by papers
published between 1900 and 2005. Three measures of concentration are
used: the percentage of papers that received at least one citation
(cited papers); the percentage of papers needed to account for 20, 50
and 80 percent of the citations; and, the Herfindahl-Hirschman index.
These measures are used for four broad disciplines: natural sciences
and engineering, medical fields, social sciences, and the humanities.
All these measures converge and show that, contrary to what was
reported by Evans, the dispersion of citations is actually increasing.