Should self-citations be excluded when calculating the h-index? The Hirsch index, or h-index is a widely used citation statistic that, arguably, accurately reflects the impact of a scientist. It takes into account the number of publications as well as how often those papers are cited. For example, an author with 4 publications each with at least 4 citations, has a h-index of 4. Another author with 200 publications, each cited only once, has a Hirsch index of just 1, simply because the papers are not cited more than once. A possible confounding factor in this index are self-citations. If the latter fictional author would have cited all his previous work in his latter 100 papers, their h-index would sky rocket to 100.     

Google Scholar nicely provides the h-index and at my institution they use Google Scholar to calculate the h-index for every researcher. However, Google Scholar includes self-citations, while I have heard colleagues from other institutions say that a h-index should not include self-citations, for reasons illustrated above. 

Interestingly, the widely used journal impact factor (JIF) from Thomson Reuters does include self-citations (Shema, 2012).

My question is: should the h-index include or exclude self-citations? Is there a consensus reached on this topic? If there is no consensus, should the h-index then not be accompanied by an identifier to clarify which of the two methods was adopted to calculate it?

Reference
- Shema, Sci Am blogs, 2012
First and foremost, I recommend reading the related question: "Why is it said that judging a paper by citation count is a bad idea?"  That question may help relieve some of your concern about the importance of having an answer for this question.

Now, turning to H-index: to the best of my knowledge, there is no consensus as to whether self-citations should count or not count.  Saying whether self-citations are included might be useful, but then it would also be useful to know quite a bit more about how the database for computing an H-index is being constructed.

My own thinking on pros and cons goes as follows:


Omitting self-citations means you get a clearer picture of whether other people are paying attention to one's work.
Self-citation is also entirely appropriate and legitimate and at moderate levels can be a good indicator of a healthy and ongoing research program.
Defining self-citation is not entirely obvious, when co-authors are taken into account.  Consider the following: if A and B co-author a paper, and then B cites the paper, should that count as a self-citation for A too?  It's not A who is citing, but the citation still might be "discounted."
Finally, precise values of H-index are not very valuable in any case, since bibliometrics are not very good at evaluating scientific impact.


Given all of these things, I personally think the best thing to do is to count self-citation in H-index and mark it clearly as such.