Impact of country self-citations on bibliometric indicators and ranking of most productive countries

The aim of the present work is to determine the share of country self-citations and to analyze its impact on total citations, average citation per paper, % cited publications and ranking of top ten most research productive countries over the period 1996–2015 using Scopus database. It was found that the mean and median of the country self-citation rates of these countries were 28.0 ± 3.8% and 22.9 ± 12.1% respectively and ranged from 17.8% (Canada) to 54.9% (China) over the studied period. United States (45.6%) ranked second country with % self-citation after China (54.9%). Country self-citations and/or its percentage were highly and positively correlated with total publications, total citations, cited publications and international collaboration. On the other hand, a strong negative correlation was observed between country self-citations with both average net-citation per paper and per capita publication. Also, significant impact of self-citation on total citations, average citation per paper and % cited publications was observed. China in total citations and United States in average citation per paper and % cited publications, were the most affected nations in rankings among all the studied nations. Among top 10 countries, China contains the highest share of self-citations in both average citation per paper (55.1%) and % cited publications (37.9%). Thus, self-citation has a strong impact on the top country’s scholarly performance. Some implications/recommendations were suggested to deal with country self-citation phenomenon. Shortly, excluding self-citation from calculating various citation-based bibliometric indicators will not remove the entire effect, but at least, it will produce a more reliable and real impact of each publication.