Open Conference Service, ELPUB2008

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Open Access Citation Rates and Developing Countries
Michael Norris, Charles Oppenheim, Fytton Rowland

Last modified: 2008-06-13



As part of a larger study of the citation advantage of Open Access (OA) , a study was mounted to see whether a higher proportion of citations to OA articles came from authors based in countries where funds for the purchase of journals were short. Mathematics was chosen as the field to be studied, because no special programme for access in developing countries, such as HINARI, covers it. The results showed that the majority of citations were given by Americans to Americans, but the admittedly small number of citations from authors in developing countries do indeed seem to show a higher proportion of citations being given to OA articles than is the case for citations from developed countries.


One of the basic arguments for OA is that those who cannot afford access to peer-reviewed journal articles could do so if the authors of these articles self-archived their work somewhere on the World Wide Web. It should follow then that a higher percentage of those who cite these OA articles ought to come from countries where access to expensive journals is limited. A number of schemes, such a HINARI and AGORA, exist to provide access to scholarly information inexpensively to users in developing countries, but not all disciplines are covered by these. In the overall larger study, four subjects (sociology, economics, ecology and mathematics) were selected, and a large number of papers were investigated to discover whether they were available on an OA basis anywhere. Citation data on all these papers were collected and subjected to statistical analyses of various kinds to establish whether or not OA availability of itself correlates with a greater number of citations to an article. As part of the larger study, mathematics - which is not covered by any of the assistance schemes - was chosen for an investigation of citation of articles by authors based in developing countries, the hypothesis being that these authors would be unlikely to have access to expensive toll access (TA) journals.


In the main project, articles from high impact journals were sought using various search tools (OAIster, OpenDOAR, Google Scholar, and finally Google), and their availability or non-availability with OA noted. Citations to them were then retrieved using the ISI Web of Science databases. The country of origin of cited and citing articles was decided by the first author's affiliation. Countries were classified by their per capita income using the World Bank's categories (see Table 1), and were also grouped by their geographical location into twelve groups (see Table 2). Citation ratios for the TA group and the OA group of articles were calculated separately.


In the overall sample, 1158 mathematics journals articles were taken from 16 high impact journals. Only citation links from other-author citations were counted; all other types of author and journal self-citations were discarded. After this, 365 of the articles were then uncited. All of the citation links to the remaining 793 articles were then analysed.


For TA articles, the highest ratio of citing to cited articles occurs for citing authors in those countries in the lower middle income bracket, regardless of the nationality of origin of the cited articles. If all but the high income level countries are taken together, then the citation ratio is 4.45 for the TA articles and 9.79 for the OA articles. However, the overwhelming majority of articles are both authored and cited from the high-income countries. Table 1 gives the full data, divided into TA and OA articles, and by the four income categories of the first author's country of residence:

Table 1. Ratio of citing to cited articles by national income groups
OA Status World Bank classification by per capita income
TA Articles Low Lower middle Upper middle High
TA cited articles (298) 2 21 19 256
TA citing articles (935) 6 106 75 748
Ratio of citing to cited articles 3 5.05 3.95 2.92
OA Articles Low Lower middle Upper Middle High
OA cited articles (495) 1 14 18 462
OA citing articles (2097) 17 180 126 1774
Ratio of citing to cited articles 17 12.85 7 3.84

Overall there is a tendency for authors to cite work from their own country preferentially. Table 2 shows all the citations, analysed by whether there was a match or not between the nationality of the authors of the citing work and of the cited work. Here 'Europe' means 'Rest of Europe, excluding those countries that are identified individually in the table.

Table 2. Citations by author country


The USA cites itself more than anyone else, which is not surprising given its level of authorship. The other developed countries except for Japan are all at about the same level in terms of within-nation citation. Table 1 suggests that while there is modest difference between the citation ratios of OA and TA articles for citations given by authors in the developed world (3.84 versus 2.92), the difference becomes much greater when citations given by authors from the developing world are studied. The sample from the lowest income countries is very small, but the results from the larger sample in the lower middle income group of countries are striking: a citation ratio of 12.85 for OA articles versus 5.05 for TA articles.