Abstract(s)
This article 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 article analyses changes in the concentration of citations received (2- and 5-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% of the citations; and the Herfindahl-Hirschman
index (HHI). 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.