OECD Bibliometric indicators. 2024 edition highlights

OECD Bibliometric Indicators

2024 edition highlights

Key points on scientific publishing trends

• Stabilised growth: In 2022, global scientific publication output stabilised, marking a "new normal" after the major surge in 2020-2021 with the mobilisation of science for COVID-19. Nearly 8 million individuals authored approximately 3.5 million documents

• China (People’s Republic of) and India’s rise: China and India increased their share of world’s total and highly-cited publications, while the shares of the OECD and EU27 declined. In 2022, China accounted for 29% of the world’s top 10% most-cited publications, whilst the United States and the EU27 saw their respective shares fall to 17% and 18%, respectively

• International collaboration: Although international scientific collaboration has grown over the past decade, this trend has slowed since 2018. Collaboration intensity has remained stable in the EU and the United States and declined in China.

• Scientific mobility: Significant shifts in scientific mobility patterns show that the EU27 and China have become more attractive destinations for publishing scientists.

China and India are playing an increasing role as scientific powerhouses

Growth in the number of indexed peer-reviewed scientific publications experienced a global slowdown in 2022, after surging in 2021, signalling a potential 'return to normal' following the major mobilisation of science to fight the COVID-19 pandemic. Whilst publishing by authors based in the EU27, the United States and other OECD countries declined in absolute terms, scientific publication output continued to increase at a fast pace in China and India (Figure 1) Experimental analysis, sensitive to effective disambiguation practices and assumptions, suggests that nearly eight million presumed-unique individuals were listed as authors of scientific publications in 2022. After growing at 10% annual rates in both 2020 and 2021, author numbers increased in 2022 at a more sustainable and historically comparable rate of 5%.

Figure 1. Volume of scientific publications in leading economies, 2012-2022

Thousands of publications, allocated on a fractional count basis

China

United

EU27

India

scale)

Note: Analysis focused on citable peer-reviewed scientific publications, include articles, reviews and indexed conference proceedings. “Rest of the world” refers to the global publication output excluding the economies on display. Individual publications with contributors from different territories are allocated to economies on a fractional count basis.

Source: OECD (2024). Bibliometric indicators. OECD calculations based on Scopus Custom Data, Elsevier, V1.2024, April 2024

The global landscape in highly-cited scientific publishing keeps evolving

Since not all publications make comparable contributions to scientific knowledge, using information on citations helps provide an approximate view of scientific output relevance and impact for international comparisons The OECD Bibliometric Indicators compute the number of publications among the world’s 10% most-cited publications by categories defined by year of publication, domain and type of document, to account for differences in citation patterns that need not reflect output impact The results presented in Figure 2 show that China and India’s footprint on the world’s top-cited scientific publication corpus has also been increasing, reaching close to 30% and 5% of the world’s top-cited total in 2022, respectively. On that measure, both the EU27 and the United States stood at slightly below 20%

Figure 2 Top-cited scientific publication output by leading economies, 2012 and 2022

As a percentage of the world's top 10% most-cited publications, based on fractional counts

Source: OECD (2024). Bibliometric indicators. OECD calculations based on Scopus Custom Data, Elsevier, Version 1.2024, April 2024.

International comparisons aiming to reflect citation impact also need to account for differences in the total volume of scientific publishing. The ratio of a country’s world’s most-(10%) cited publications to its total number of publications provides an intensity indicator of scientific output quality China’s domestic rate of highly cited scientific output reached 11% in 2022, slightly over the 10% global benchmark, and up from less than 6% ten years before. The EU27 area stood at 10% while the combined OECD area was slightly higher at 11%. Under current membership, fewer than half of 38 OECD countries exceed the 10% benchmark. A majority have seen their “top-cited” publication intensity decline over the last decade (Figure 3).

Figure 3. Top-cited scientific publication intensity, OECD countries, 2012 and 2022

Domestic publications in global 10% most-cited, as percentage of all domestic publications, based on fractional counts

Source: OECD (2024). Bibliometric indicators OECD calculations based on Scopus Custom Data, Elsevier, Version 1.2024, April 2024.

International scientific collaboration is up from one decade ago there are signs it is slowing down

Co-authorship of scientific publications involving authors with institutional affiliations in different countries provides an indication of international scientific collaboration. International collaboration intensity can be measured as the number of a reference territory’s publications where the set of listed affiliations includes at least one affiliation abroad, as a percentage of the total number of publications attributed to that territory. The largest science publishing economies, with the sole exception of the Russian Federation, saw an increase in international collaboration intensity between 2012 and 2022 (Figure 4). The United Kingdom has the highest collaboration intensity within this group, followed by Australia and France. The Asian economies exhibit lower than average international collaboration Australia, Brazil, India, the United Kingdom have experienced the biggest proportional increase in collaboration intensity

Figure 4. International scientific collaboration intensity, selected economies, 2012 and 2022

As a percentage of domestically-authored publications, based on fractional counts

Source: OECD (2024). Bibliometric indicators OECD calculations based on Scopus Custom Data, Elsevier, Version 1.2024, April 2024.

More recent data however suggests that the trend towards increasing international collaboration has lost momentum and might be partly unfolding China’s international collaboration intensity has significantly declined from 2020 to 2022 India’s collaboration rate surpassed China’s in 2021 (Figure 5) Whilst the international collaboration rate for the United Kingdom kept on increasing, the external collaboration rate for the United States and the EU27 area (also that of its major economy, Germany) remained virtually unchanged since 2018

Figure 5 Trends in international scientific collaboration, selected countries, 2012 and 2022

As a percentage of domestically-authored publications, based on fractional counts

Source: OECD (2024). Bibliometric indicators OECD calculations based on Scopus Custom Data, Elsevier, Version 1.2024, April 2024.

Bilateral collaboration shows which economies work more with which

Data on affiliations in scientific publications also reveal how scientific based across different economies collaborate with each other and how these dynamics contribute to explaining aggregate collaboration trends In 2022, scientific authors based in the United States and the EU27 were their respective main collaboration partners beyond their boundaries (Figure 6A). Authors based in China were the second most likely collaborators for authors based in the United States in 2022 China’s collaboration intensity with the United States declined over the 2018-2022 period because growth in collaborations did not keep up with the total growth in publications with authors in China (Fig. 6B). In contrast, China’s collaboration intensity with other economies has not declined that fast. India’s collaboration has expanded significantly in particular with EU27, now its main partner, and Saudi Arabia (Fig. 6D)

Figure 6. Main scientific collaboration partners, selected economies, 2018 and 2022

Joint scientific publications as a percentage of all domestic publications in the reference economy, whole counts

How to read this chart (Panel A): Over 14% of 2022 publications with US-based authors were conducted in collaboration with authors based in the EU27 area in 2022, slightly up from 2018 (US panel) The counterpart figure in the EU27 panel C shows that 10% of publications by EU27-based authors were published with US-affiliated authors. The difference is explained by the larger number of EU27 publications compared to the United States (same numerator, different denominator)

Note: The indicator in this figure has been computed on a whole count basis, namely numbers of institutional affiliation-implied collaborations between the reference economy and its main partners in numerator and the total reference economy’s publications in denominator. Single authored publications with more than one institutional affiliation count as collaborations. The collaboration figures presented for the E27 focus on external collaboration and do not include collaboration across its member states.

Source: OECD (2024). Bibliometric indicators OECD calculations based on Scopus Custom Data, Elsevier, Version 1.2024, April 2024.

A. United States

B. China

C. EU27

D. India

Data on affiliations indicate significant shifts in international mobilty flows

Scientific publications provide approximate information on international mobility through the analysis of changes in affiliation records of scientific authors over time. The largest scientific publishing economies have experienced major shifts according to implied inflow and outflow mobility episodes recorded in 2016 and 2022 While the EU27 area experienced a significant negative net flow in 2016, it attracted over 4 000 scientific authors in net terms in 2022 (Figure 7). Over that period, China became a net recipient of authors, while the United States saw its position as largest net attractor shift below the EU27 and Canada The United Kingdom turned from a net attractor in 2016 to a net donor in 2022 while India maintained its status as the largest donor.

Figure 7. International mobility of scientific authors, 2016 and 2022

Difference between inflows and outflows implied from author’s affiliation changes recorded each year

Source: OECD (2024). Bibliometric indicators OECD calculations based on Scopus Custom Data, Elsevier, Version 1.2024, April 2024.

There are also qualitative differences across groups of scientific authors with different international mobility profiles. Data on the citation impact of scientific authors according to their mobility records shows that internationally mobile authors tend to have, with the exception of the United Kingdom and Iceland, a higher expected citation impact than those who do not have a prior mobility record (stayers) (Figure 8). Comparing across different mobile profiles (inflows, outflows and returnees), in cases like the United States and Germany the incoming authors are the most “impactful”, whereas for many other others including China and India, it is authors who moved abroad who show a higher expected citation impact. In nearly all cases, authors who left and eventually returned to the reference territory contribute to raising a country’s expected citation impact

8 International mobility profiles and differences in expected citation impact, 2022

Note: The expected citation impact is based on an average of the relevant authors’ publications’ Scimago Journal Rank 2022 scores, a measure of scientific influence of scholarly journals that accounts for the number and centrality of citations received.

Source: OECD calculations based on Scopus Custom Data, Elsevier, Version 1.2024, April 2024; and Scimago Journal Rankings.

Figure

The surge in scientific publication output on Artificial Intelligence (AI) remains strong

The surge in research in AI is reflected in the dramatic increase in scientific publication output in this area (Box 1) between 2012 and 2022 (Figure 9) China published six times times as many publications in AI in 2022 compared to what it did in 2012, while in the OECD area the number of AI publications nearly quadrupled The growth rate in AI scientific publishing has been exceeding by a very high margin than that of other scientific domains India experienced the fastest growth in the share of AI publications over total scientific publications, from less than 3% to 10% (Figure 10).

Figure 9. Number of scientific publications on AI, selected countries, 2012-2022

Fractional counts

Source: OECD (2024). Bibliometric indicators OECD calculations based on Scopus Custom Data, Elsevier, Version 1.2024, April 2024.

Figure 10. Economies with the largest volume of AI publications, 2012-2022

As a percentage of total scientific publications

China EU27 India United States Korea Germany

Source: OECD (2024). Bibliometric indicators OECD calculations based on Scopus Custom Data, Elsevier, Version 1.2024, April 2024.

Box 1. Scientific publications on Artificial Intelligence (AI)

Since scientific research that builds on and helps expand AI knowledge is not circumscribed to a specific domain, the identification of scientific publications in this area is based on a list of AI-related keywords to search the full body of abstracts in the Scopus database The list of keywords is based on an iterative selection process. The selection of documents requires that for a publication to be considered as AI-related, a minimum of two AI keywords must be present. For more details on this methodology, see: Baruffaldi, S., et al. (2020), "Identifying and measuring developments in artificial intelligence: Making the impossible possible", OECD Science, Technology and Industry Working Papers, No. 2020/05, OECD Publishing, Paris, https://doi.org/10.1787/5f65ff7e-en

About the OECD Bibliometric indicators, April 2024 edition

This publication uses patterns of publishing in indexed peer-reviewed scientific journals to provide an indication of trends in scientific research. These can be relevant for better understanding national science and innovation systems on dimensions such as publication output and specialisation, citation impacts, collaboration and talent mobility

The OECD Bibliometric Indicators published in April 2024 are based on Elsevier’s Scopus Custom Data This edition is based on data provided by Elsevier in January 2024 and provides a comprehensive view of indicators up to and including 2022 Indicators for 2023 have not yet been compiled because of incomplete indexed data for that year, particularly information on citations to publications published on that year The OECD Bibliometric indicators are typically updated on an annual basis towards the end of Q1.

An expanded selection of the OECD Bibliometric Indicators is available through the STI.Scoreboard platform: http://oe.cd/sti-scoreboard

The STI.Scoreboard platform can be used to retrieve, visualise and compare statistical indicators of science, technology and innovation systems across OECD countries and several other economies. The platform can be used to generate charts, download data and figures or to save and share them. This “Highlights” publication provides embedded links under Sources notes to the STI.Scoreboard pages with the relevant data and visualisations.

In addition, there are three data sets of bibliometric indicators available at OECD corporate statistical dissemination tool: https://data-explorer.oecd.org/ under Science, technology and innovation -> Bibliometric indicators ->

– Bibliometric indicators of implied bilateral mobility flows

– Bibliometric indicators of international collaboration

– Bibliometric indicators, by field and country

For more information see: http://oe.cd/scientometrics

This document and any map included herein are without prejudice to the status of or sovereignty over any territory, to the delimitation of international frontiers and boundaries and to the name of any territory, city or area.

The statistical data for Israel are supplied by and under the responsibility of the relevant Israeli authorities. The use of such data by the OECD is without prejudice to the status of the Golan Heights, East Jerusalem and Israeli settlements in the West Bank under the terms of international law.

Please cite this note as: OECD (2024). “OECD Bibliometric indicators. 2024 edition highlights”, OECD Directorate for Science, Technology and Innovation, https://issuu.com/oecd.publishing/docs/2024_bibliometrics_april_highlights