|Rank||Country||Papers||Citations||Citations per paper|
reports and review articles) indexed by Thomson Reuters. Articles are assigned to a category based on the journals in which they were published and Thomson Reuters’ journal-to-category field-definition scheme. Both articles tabulated and citation counts to those articles are for the period indicated.
Here our ranking in all fields of the sciences and social sciences is by citations per paper – among nations
that published 50,000 or more papers for the period – to reveal weighted impact. For articles with multiple authors from different nations, each nation receives full, not fractional, citation credit. Essential Science Indicators lists nations ranked in the top 50 per cent for a field over a given period, based on total citations.
In all fields surveyed, 148 nations or territories are listed, meaning 296 were surveyed. Thirty-two nations or territories produced at least 50,000 papers indexed by Thomson Reuters from January 1998 through April 2008.
Of course, the mix of research in different fields produced by each nation varies, and since different fields exhibit different average rates of citation, the above data represent a blended measure: those that produced more papers in high-impact fields have an advantage over those that disproportionately published in low-impact fields. Likewise, those that published greater numbers of papers in languages other than English have a disadvantage compared with those publishing exclusively in English, the lingua franca of modern research.