This is actually an older post, but it somehow got lost and I’m reposting it.
Lately I looked for some statistical data on how many papers get published every year. I couldn't find data but I found some interesting comparison on the scientific output of different countries. As expected the USA has the most papers and the most citations but what occurred to me is that many of the citations are actually self-citations. Since I think self-citations shouldn't count I did some analysis to factor out self-citations.
In order to find the "real" citations I removed all self-citations (luckily the numbers were included in the data). After this the USA still has the most citations and most papers but regarding the citations per paper the picture changes completely. The USA drops from rank 4 counting all citations to rank 18 when removing self-citations. The USA is the only country whose rank changes by more than 5 spots in the comparison. See the figures for more information.
The first figure shows the number of citations per paper when self-citations are excluded. The number in parentheses shows the number of gained (positive numbers) or lost ranks (negative numbers) compared to when counting all citations.
For comparison Figure 2 shows the statistics when counting all citations.
Figure 3 finally shows the percentage of self-citations. China and the USA are the only countries wit more than 45% self-citations.
I took the data from http://www.scimagojr.com/countryrank.php and for the years 1996-2012.
I included only countries with more than 100'000 published papers.
Good for me that Switzerland is ranked on top in all three figures :-)