The decline in the concentration of citations, 1900-2007 (0809.5250v1)

Abstract: This paper challenges recent research (Evans, 2008) reporting that the concentration of cited scientific literature increases with the online availability of articles and journals. Using Thomson Reuters' Web of Science, the present paper analyses changes in the concentration of citations received (two- and five-year citation windows) by papers published between 1900 and 2005. Three measures of concentration are used: the percentage of papers that received at least one citation (cited papers); the percentage of papers needed to account for 20, 50 and 80 percent of the citations; and, the Herfindahl-Hirschman index. These measures are used for four broad disciplines: natural sciences and engineering, medical fields, social sciences, and the humanities. All these measures converge and show that, contrary to what was reported by Evans, the dispersion of citations is actually increasing.

An Analysis of the Declining Concentration in Scientific Citations (1900-2007)

This paper presents a rigorous examination of the trends in citation concentration across an expansive historical framework from 1900 to 2007. The authors Vincent Larivière, Yves Gingras, and Éric Archambault provide empirical evidence contradicting the prevalent notions proposed by Evans (2008) regarding the increasing concentration of citations amid the rise of online scholarly publishing. Through a robust methodological approach, the authors assess trends in citation concentration employing three distinct measures: the proportion of papers that receive at least one citation, the distribution of papers accounting for 20%, 50%, and 80% of all citations, and the Herfindahl-Hirschman Index (HHI).

Key Findings

The paper challenges the hypothesis that an increase in digital access to academic journals results in a more concentrated citation distribution. By leveraging data from the Thomson Reuters Web of Science, the authors uncover a general trend toward decreasing citation concentration, particularly within the natural sciences and engineering (NSE), medical fields (MED), and social sciences (SS).

1. Proportion of Cited Papers: Over the observed period, the percentage of papers receiving at least one citation has increased notably since the 1970s. In MED fields in 2005, citations were distributed across 80% of published papers. Similar patterns were present in NSE and SS, although with slightly lower percentages.
2. Concentration of Citations: There has been an observable increase in the dispersion of citations. For instance, in 2005, 33% of MED papers and 28% of NSE papers accounted for 80% of citations, signifying a broader distribution across a larger set of papers compared to earlier decades.
3. Herfindahl-Hirschman Index: A measurable decline in citation concentration is observed through HHI values, with papers published in 2005 displaying the lowest concentration in citation history for most fields except humanities, due to their unique citing behaviors.

Implications and Theoretical Considerations

The findings refute the claim of increased concentration asserted by Evans (2008) and suggest a more democratic dissemination of scientific knowledge. This dispersion indicates a shift towards utilizing a broader spectrum of the published stock. Moreover, the broader citation patterns could provide a more comprehensive foundation for scientific progression, as research is synthesized from a wider array of sources.

Theoretically, this work prompts a reassessment of how online access impacts citation behavior. While online availability has increased accessibility, it appears not to deter the use of older or less immediately significant works. Thus, the scientific community may not be narrowing its focus but rather expanding its reliance on a diverse collection of literature in a global scholarly discourse.

Practical Applications and Future Developments

For institutions and policymakers, these findings highlight the importance of providing extensive access to a wide range of scientific papers beyond merely high-impact or recent publications. It underscores the necessity to facilitate open-access repositories and comprehensive databases that promote equitable access to the breadth of scientific research output.

Future research could dissect the digital influences in the citation landscape more precisely, exploring factors such as search engine algorithms, access policies, and the role of thematic aggregators in shaping citation behavior. Investigations could focus on the evolving dynamics across various scientific fields, especially those with distinct citation patterns like the humanities, to comprehend the universality of the observed trends.

This paper's contribution lies in its comprehensive examination of long-term citation dynamics, establishing a well-defined narrative against the ideology of an increasingly insular scientific forum amid digital evolution. As scholarly communication continues to evolve, the ongoing analysis of citation structures will remain pivotal in understanding the broader implications on scientific knowledge production and dissemination.