1.4.4 Contemporary h-index
A disadvantage of the h-index is that it cannot decline. That means that academics who “retire” after 10-20 active years of publishing maintain their high h-index even if they never publish another paper. In order to address this issue, the contemporary h-index was proposed by Sidiropoulos, Katsaros & Manolopoulos (2006).
It adds an age-related weighting to each cited article, giving (by default; this depends on the parameterization) less weight to older articles. The weighting is parameterized; the Publish or Perish implementation uses gamma=4 and delta=1, like the authors did for their experiments. This means that for an article published during the current year, its citations account four times. For an article published 4 years ago, its citations account only one time. For an article published 6 years ago, its citations account 4/6 times, and so on.
For junior academics the contemporary h-index is generally close to their regular h-index as most of the papers included in their h-index will be recent. For more established academics there can be a substantial difference between the two indices, indicating that most of the papers included in their h-index have been published some time ago. As such the contemporary h-index often provides a fairer comparison between junior and senior academics than the regular h-index.