Showing papers in "Scientometrics in 2013"

Citation time window choice for research impact evaluation

Abstract: This paper aims to inform choice of citation time window for research evaluation, by answering three questions: (1) How accurate is it to use citation counts in short time windows to approximate total citations? (2) How does citation ageing vary by research fields, document types, publication months, and total citations? (3) Can field normalization improve the accuracy of using short citation time windows? We investigate the 31-year life time non-self-citation processes of all Thomson Reuters Web of Science journal papers published in 1980. The correlation between non-self-citation counts in each time window and total non-self-citations in all 31 years is calculated, and it is lower for more highly cited papers than less highly cited ones. There are significant differences in citation ageing between different research fields, document types, total citation counts, and publication months. However, the within group differences are more striking; many papers in the slowest ageing field may still age faster than many papers in the fastest ageing field. Furthermore, field normalization cannot improve the accuracy of using short citation time windows. Implications and recommendations for choosing adequate citation time windows are discussed.

Global maps of science based on the new Web-of-Science categories

Abstract: In August 2011, Thomson Reuters launched version 5 of the Science and Social Science Citation Index in the Web of Science (WoS). Among other things, the 222 ISI Subject Categories (SCs) for these two databases in version 4 of WoS were renamed and extended to 225 WoS Categories (WCs). A new set of 151 Subject Areas was added, but at a higher level of aggregation. Perhaps confusingly, these Subject Areas are now abbreviated "SC" in the download, whereas "WC" is used for WoS Categories. Since we previously used the ISI SCs as the baseline for a global map in Pajek (Pajek is freely available at http://vlado.fmf.uni-lj.si/pub/networks/pajek/ ) (Rafols et al., Journal of the American Society for Information Science and Technology 61:1871---1887, 2010) and brought this facility online (at http://www.leydesdorff.net/overlaytoolkit ), we recalibrated this map for the new WC categories using the Journal Citation Reports 2010. In the new installation, the base maps can also be made using VOSviewer (VOSviewer is freely available at http://www.VOSviewer.com/ ) (Van Eck and Waltman, Scientometrics 84:523---538, 2010).

Prediction of emerging technologies based on analysis of the US patent citation network

Abstract: The network of patents connected by citations is an evolving graph, which provides a representation of the innovation process. A patent citing another implies that the cited patent reflects a piece of previously existing knowledge that the citing patent builds upon. A methodology presented here (1) identifies actual clusters of patents: i.e., technological branches, and (2) gives predictions about the temporal changes of the structure of the clusters. A predictor, called the citation vector, is defined for characterizing technological development to show how a patent cited by other patents belongs to various industrial fields. The clustering technique adopted is able to detect the new emerging recombinations, and predicts emerging new technology clusters. The predictive ability of our new method is illustrated on the example of USPTO subcategory 11, Agriculture, Food, Textiles. A cluster of patents is determined based on citation data up to 1991, which shows significant overlap of the class 442 formed at the beginning of 1997. These new tools of predictive analytics could support policy decision making processes in science and technology, and help formulate recommendations for action.

A preliminary test of Google Scholar as a source for citation data: a longitudinal study of Nobel prize winners

Abstract: Most governmental research assessment exercises do not use citation data for the Social Sciences and Humanities as Web of Science or Scopus coverage in these disciplines is considered to be insufficient. We therefore assess to what extent Google Scholar can be used as an alternative source of citation data. In order to provide a credible alternative, Google Scholar needs to be stable over time, display comprehensive coverage, and provide non-biased comparisons across disciplines. This article assesses these conditions through a longitudinal study of 20 Nobel Prize winners in Chemistry, Economics, Medicine and Physics. Our results indicate that Google Scholar displays considerable stability over time. However, coverage for disciplines that have traditionally been poorly represented in Google Scholar (Chemistry and Physics) is increasing rapidly. Google Scholar's coverage is also comprehensive; all of the 800 most cited publications by our Nobelists can be located in Google Scholar, although in four cases there are some problems with the results. Finally, we argue that Google Scholar might provide a less biased comparison across disciplines than the Web of Science. The use of Google Scholar might therefore redress the traditionally disadvantaged position of the Social Sciences in citation analysis.

Capturing new developments in an emerging technology: an updated search strategy for identifying nanotechnology research outputs

Abstract: Bibliometric analysis of publication metadata is an important tool for investigating emerging fields of technology. However, the application of field definitions to define an emerging technology is complicated by ongoing and at times rapid change in the underlying technology itself. There is limited prior work on adapting the bibliometric definitions of emerging technologies as these technologies change over time. The paper addresses this gap. We draw on the example of the modular keyword nanotechnology search strategy developed at Georgia Institute of Technology in 2006. This search approach has seen extensive use in analyzing emerging trends in nanotechnology research and innovation. Yet with the growth of the nanotechnology field, novel materials, particles, technologies, and tools have appeared. We report on the process and results of reviewing and updating this nanotechnology search strategy. By employing structured text-mining software to profile keyword terms, and by soliciting input from domain experts, we identify new nanotechnology-related keywords. We retroactively apply the revised evolutionary lexical query to 20 years of publication data and analyze the results. Our findings indicate that the updated search approach offers an incremental improvement over the original strategy in terms of recall and precision. Additionally, the updated strategy reveals the importance for nanotechnology of several emerging cited-subject categories, particularly in the biomedical sciences, suggesting a further extension of the nanotechnology knowledge domain. The implications of the work for applying bibliometric definitions to emerging technologies are discussed.

Source normalized indicators of citation impact: an overview of different approaches and an empirical comparison

Abstract: Different scientific fields have different citation practices. Citation-based bibliometric indicators need to normalize for such differences between fields in order to allow for meaningful between-field comparisons of citation impact. Traditionally, normalization for field differences has usually been done based on a field classification system. In this approach, each publication belongs to one or more fields and the citation impact of a publication is calculated relative to the other publications in the same field. Recently, the idea of source normalization was introduced, which offers an alternative approach to normalize for field differences. In this approach, normalization is done by looking at the referencing behavior of citing publications or citing journals. In this paper, we provide an overview of a number of source normalization approaches and we empirically compare these approaches with a traditional normalization approach based on a field classification system. We also pay attention to the issue of the selection of the journals to be included in a normalization for field differences. Our analysis indicates a number of problems of the traditional classification-system-based normalization approach, suggesting that source normalization approaches may yield more accurate results.

A co-word analysis of library and information science in China

Abstract: This study aims to reveal the intellectual structure of Library and Information Science (LIS) in China during the period 2008---2012 utilizing co-word analysis. The status and trends of LIS in China are achieved by measuring the correlation coefficient of selected keywords extracted from relevant journals in the Chinese Journal Full-Text Database. In co-word analysis, multivariate statistical analysis and social network analysis are applied to obtain 13 clusters of keywords, a two-dimensional map, centrality and density of clusters, a strategic diagram and a relation network. Based on these results, the following conclusions can be drawn: (i) LIS in China has some established and well-developed research topics; (ii) a few emerging topics have a great potential for development; and (iii), the research topics in this LIS field are largely decentralized as a whole, where there are many marginal and immature topics.

Identifying technological competition trends for R&D planning using dynamic patent maps: SAO-based content analysis

Abstract: Patent maps showing competition trends in technological development can provide valuable input for decision support on research and development (RD the structures of a patent encode the key findings of the invention and expertise of its inventors. Therefore, this paper introduces a method of constructing dynamic patent maps using SAO-based content analysis of patents and presents several types of dynamic patent maps by combining patent bibliographic information and patent mapping and clustering techniques. Building on the maps, this paper provides further analyses to identify technological areas in which patents have not been granted ("patent vacuums"), areas in which many patents have actively appeared ("technological hot spots"), R&D overlap of technological competitors, and characteristics of patent clusters. The proposed analyses of dynamic patent maps are illustrated using patents related to the synthesis of carbon nanotubes. We expect that the proposed method will aid experts in understanding technological competition trends in the process of formulating R&D strategies.

Studying scientific migration in Scopus

Abstract: An exploration is presented of Scopus as a data source for the study of international scientific migration or mobility for five study countries: Germany, Italy, the Netherlands, UK and USA. It is argued that Scopus author-affiliation linking and author profiling are valuable, crucial tools in the study of this phenomenon. It was found that the UK has the largest degree of outward international migration, followed by The Netherlands, and the USA the lowest. Language similarity between countries is a more important factor in international migration than it is in international co-authorship. During 1999---2010 the Netherlands showed a positive "migration balance" with the UK and a negative one with Germany, suggesting that in the Netherlands there were more Ph.D. students from Germany than there were from the UK, or that for Dutch post docs stage periods in the UK were more attractive than those in Germany. Comparison of bibliometric indicators with OECD statistics provided evidence that differences exist in the way the various study countries measured their number of researchers. The authors conclude that a bibliometric study of scientific migration using Scopus is feasible and provides significant outcomes. They make suggestions for further research.

LIS journals scientific impact and subject categorization: a comparison between Web of Science and Scopus

Abstract: The study compares the coverage, ranking, impact and subject categorization of Library and Information Science journals, specifically, 79 titles based on data from Web of Science (WoS) and 128 titles from Scopus. Comparisons were made based on prestige factor scores reported in 2010 Journal Citation Reports and SCImago Journal Rank 2010 and noting the change in ranking when the differences are calculated. The rank normalized impact factor and the Library of Congress Classification System were used to compare impact rankings and subject categorization. There was high degree of similarity in rank normalized impact factor of titles in both WoS and Scopus databases. The searches found 162 journals, with 45 journals appearing in both databases. The rankings obtained for normalized impact scores confirm higher impact scores for titles covered in Scopus because of its larger coverage of titles. There was mismatch of subject categorization among 34 journal titles in both databases and 22 of the titles were not classified under Z subject headings in the Library of Congress catalogue. The results revealed the changes in journal title rankings when normalized, and the categorization of some journal titles in these databases might be incorrect.

Assessing gender balance among journal authors and editorial board members

Abstract: The study of journal authorship and editorial board membership from a gender perspective is addressed in this paper following international recommendations about the need to obtain science and technology indicators by gender. Authorship informs us about active scientists who contribute to the production and dissemination of new knowledge through journal articles, while editorial board membership tells us about leading scientists who have obtained scientific recognition within the scientific community. This study analyses by gender the composition of the editorial boards of 131 high-quality Spanish journals in all fields of science, the presence of men and women as authors in a selection of 36 journals, and the evolution of these aspects from 1998 to 2009. Female presence is lower than male presence in authorship, editorial board membership and editorship. The presence of female authors is slightly lower than the presence of women in the Spanish Higher Education sector and doubles female presence in editorial boards, which mirrors female presence in the highest academic rank. The gender gap tends to diminish over the years in most areas, especially in authorship and very slightly in editorial board membership. Large editorial boards and having a female editor-in-chief are positively correlated with women presence in editorial boards. The situation of women in Spanish science is further assessed in an international context analysing a selection of international reference journals. The usefulness of journal-based indicators to monitor the situation of men and women in science and to assess the success of policies oriented to enhance gender equality in science is finally discussed.

Global trends of solid waste research from 1997 to 2011 by using bibliometric analysis

Abstract: This study explores a bibliometric approach to quantitatively assessing current research trends on solid waste, by using the related literature published between 1997 and 2011 in journals of all the subject categories of the Science Citation Index. The articles acquired from such literature were concentrated on the general analysis by publication type and language, characteristics of articles outputs, country, subject categories and journals, and the frequency of title-words and keywords used. Over the past 15 years, there had been a notable growth trend in publication outputs, along with more participation of countries/territories. The seven major industrialized countries (G7) published the majority of the world articles, while their article share was being replacing by other countries represented by BRIC countries. An analysis of the title-words, author keywords and keywords plus showed that municipal solid waste and sludge were the major research types of solid wastes and "anaerobic digestion", "wastewater" and "heavy metals" were recent major topics of solid waste research. Meanwhile, the analysis indicated the analysis technologies, represented by solid-phase extraction and tandem mass-spectrometry, were more and more widely used for solid waste research. Besides, life cycle assessment and health risk assessment were the most two frequently environmental assessment tools used for solid waste research in the 15-year research period.

Duplicate and fake publications in the scientific literature: how many SCIgen papers in computer science?

Abstract: Two kinds of bibliographic tools are used to retrieve scientific publications and make them available online. For one kind, access is free as they store information made publicly available online. For the other kind, access fees are required as they are compiled on information provided by the major publishers of scientific literature. The former can easily be interfered with, but it is generally assumed that the latter guarantee the integrity of the data they sell. Unfortunately, duplicate and fake publications are appearing in scientific conferences and, as a result, in the bibliographic services. We demonstrate a software method of detecting these duplicate and fake publications. Both the free services (such as Google Scholar and DBLP) and the charged-for services (such as IEEE Xplore) accept and index these publications.

The top-cited research works in the Science Citation Index Expanded

Abstract: This study aimed to identify and analyze the characteristics of the top-cited articles published in the Science Citation Index Expanded from 1991 to 2010. Articles that have been cited more than 1,000 times since publication to 2010 were assessed regarding their distribution in indexed journals and categories of the Web of Science. Five bibliometric indicators were used to evaluate source institutions and countries. A new indicator, the Y-index, is proposed to assess publication quantity and the character of contribution to articles. We identify 3,652 top-cited articles with 71 % originating from US. The fourteen most productive institutions were all located in US. Science, Nature, New England Journal of Medicine, and Cell hosted the most cited publications. In addition, the Y-index was successfully applied to evaluate the publication character of authors, institutions, and countries.

Doctoral dissertations of Library and Information Science in China: A co-word analysis

Abstract: The aim of this paper is to map the intellectual structure of research in doctoral dissertations of Library and Information Science in China. By use of Co-word analysis, including cluster analysis, strategic diagram and social network analysis, we studied the internal and external structure and relationship of research fields in doctoral dissertations of Library and Information Science in China. Data was collected, during the period of 1994---2011, from six public dissertation databases and ten degree databases provided by the universities/institutes which have been authorized to grant doctoral degrees of Library and Information Science in China. The results show that Wuhan University is the most important institution of doctoral education in LIS in China. The focuses of researches, including information resource, ontology, semantic web, semantic search, electronic government, information resource management, knowledge management, knowledge innovation, knowledge sharing, knowledge organization, network, information service, information need and digital library. The research fields of LIS doctoral dissertations in China are varied. Many of these research fields are still immature; accordingly, the well-developed and core research fields are fewer.

Global remote sensing research trends during 1991---2010: a bibliometric analysis

Abstract: According to the articles related to remote sensing of SCI and SSCI databases during 1991---2010, this study evaluated the geographical influence of authors by the new index (geographical impact factor), and revealed the auctorial, institutional, national, and spatiotemporal patterns in remote sensing research. Remote sensing research went up significantly in the past two decades. Imaging science & photographic technology was the important subject category. International Journal of Remote Sensing was the top active journal. All authors were mainly concentrated in North America, Western Europe, and East Asia. Jackson TJ from USDA ARS was the most productive author, Coops NC from University of British Columbia had more high-quality articles, and Running SW from University of Montana carried the greatest geographical influence. The USA was the largest contributor in global remote sensing research with the most single-country and internationally collaborative articles, and the NASA was the most powerful research institute. The international cooperation of remote sensing research increased distinctly. Co-word analysis found the common remote sensing platform and sensors, revealed the widespread adoption of major technologies, and demonstrated keen interest in land cover/land use, vegetation, and climate change. Moreover, the remote sensing research was closely correlated with the satellite development.

Examining the relationship of co-authorship network centrality and gender on academic research performance: the case of chemistry researchers in Pakistan

Abstract: This research examines the association of co-authorship network centrality (degree, closeness and betweeness) and the academic research performance of chemistry researchers in Pakistan. Higher centrality in the co-authorship network is hypothesized to be positively related to performance, in terms of academic publication, with gender having a positive moderating effect for female researchers. Using social network analysis, this study examines the bibliometric data (2002---2009) from ISI Web of Science for the co-authorship network of 2,027 Pakistani authors publishing in the field of Chemistry. A non-temporal analysis using node-level regression reports positive impact of degree and closeness and negative impact of betweeness centrality on research performance. Temporal analysis using node-level regression (time 1: 2002---2005; time 2: 2006---2009) confirms the direction of causality and demonstrates the positive association of degree and closeness centrality on research performance. Findings indicate a moderating role of gender on the relationship of both degree and closeness centrality with research performance for Pakistani female authors.

On bibliographic networks

Abstract: In the paper we show that the bibliographic data can be transformed into a collection of compatible networks. Using network multiplication different interesting derived networks can be obtained. In defining them an appropriate normalization should be considered. The proposed approach can be applied also to other collections of compatible networks. The networks obtained from the bibliographic data bases can be large (hundreds of thousands of vertices). Fortunately they are sparse and can be still processed relatively fast. We answer the question when the multiplication of sparse networks preserves sparseness. The proposed approaches are illustrated with analyses of collection of networks on the topic "social network" obtained from the Web of Science. The works with large number of co-authors add large complete subgraphs to standard collaboration network thus bluring the collaboration structure. We show that using an appropriate normalization their effect can be neutralized. Among other, we propose a measure of collaborativness of authors with respect to a given bibliography and show how to compute the network of citations between authors and identify citation communities.

Opinion paper: thoughts and facts on bibliometric indicators

Abstract: This paper aims at contributing to the on-going discussion about building and applying bibliometric indicators. It sheds light on their properties and requirements concerning six different aspects: deterministic versus probabilistic approach, application-related properties, the time dependence, normalization issues, size dependence and network indicators.

Assessing non-standard article impact using F1000 labels

Abstract: Faculty of 1000 (F1000) is a post-publishing peer review web site where experts evaluate and rate biomedical publications. F1000 reviewers also assign labels to each paper from a standard list or article types. This research examines the relationship between article types, citation counts and F1000 article factors (FFa). For this purpose, a random sample of F1000 medical articles from the years 2007 and 2008 were studied. In seven out of the nine cases, there were no significant differences between the article types in terms of citation counts and FFa scores. Nevertheless, citation counts and FFa scores were significantly different for two article types: "New finding" and "Changes clinical practice": FFa scores value the appropriateness of medical research for clinical practice and "New finding" articles are more highly cited. It seems that highlighting key features of medical articles alongside ratings by Faculty members of F1000 could help to reveal the hidden value of some medical papers.

Resilience thinking: a bibliometric analysis of socio-ecological research

Abstract: Resilience thinking is a rising topic in environmental sciences and sustainability discourse. In this paper, a bibliometric method is used to analyse the trends in resilience research in the contexts of ecological, economic, social, and integrated socio-ecological systems. Based on 919 cited publications in English which appeared between 1973 and 2011, the analysis covers the following issues: general statistical description, influential journal outlets and top cited articles, geographic distribution of resilience publications and covered case studies, national importance of resilience researchers and leading research organisations by country. The findings show that resilience thinking continues to dominate environmental sciences and has experienced a dramatic increase since its introduction in 1973. More recently, new interest has emerged for broadening the scope and applying the concept to socio-economic systems and sustainability science. The paper also shows that resilience research overall is dominated by USA, Australia, UK and Sweden, and makes the case for the need to expand this work further in the urgent need for practically oriented solutions that would help arrest further ecological deterioration.

The research guarantors of scientific papers and the output counting: a promising new approach

Abstract: We propose a method for selecting the research guarantor when papers are co-authored The method is simply based on identifying the corresponding author The method is here applied to global scientific output based on the SCOPUS database in order to build a new output distribution by country This new distribution is then compared with previous output distributions by country but which were based on whole or fractional counting, not only for the total output but also for the excellence output (papers belonging to the 10 % most cited papers) The comparison allows one to examine the effect of the different methodological approaches on the scientific performance indicators assigned to countries In some cases, there was a very large variation in scientific performance between the total output (whole counting) and output as research guarantor The research guarantor approach is especially interesting when used with the excellence output where the quantity of excellent papers is also a quality indicator The impact of excellent papers naturally has less variability as they are all top-cited papers

A bibliometric study of service innovation research: based on complex network analysis

Abstract: In the paper, we apply small world complex network theory to analyze scientific research in the field of service innovation, and discover its research focuses. Our study considers the key words and subject categories of the publications as actors to map keyword co-occurrence network and subject category co-occurrence network, and compare them with their corresponding random binary networks to judge whether these complex networks have the characteristics of small world network, in order to find the hot issues in the field by the small world network analysis. We discuss the knowledge structure in the field through analyzing 437 papers that were searched from Web of Science database over the period 1992---2011. We find that case study, service industry, service quality, market orientation, new product development, and knowledge management were the most popular keywords of the field, and also show the dynamic development of the research focuses in recent 10 years. The researchers who made most contribution in a certain field are also found out. It is concluded that there were more researchers who did investigation about service innovation in the category of Business and Economics, Engineering, Public Administration, Operations Research and Management Science, and Computer Science than those in other categories. The study suggests a quantitative method to analyze trends of scientific research in a certain field, and presents some directions of research mainstream to the researchers who may be interested in the service innovation.

Document categories in the ISI Web of Knowledge: Misunderstanding the Social Sciences?

Abstract: Thomson Reuter's ISI Web of Knowledge (or ISI for short) is used in the majority of benchmarking analyses and bibliometric research projects. Therefore, it is important to be aware of the limitations of data provided by ISI. This article deals with a limitation that disproportionally affects the Social Sciences: ISI's misclassification of journal articles containing original research into the "review" or "proceedings paper" category. I report on a comprehensive, 11 year analysis, of document categories for 27 journals in nine Social Science and Science disciplines. I show that although ISI's "proceedings paper" and "review" classifications seem to work fairly well in the Sciences, they illustrate a profound misunderstanding of research and publication practices in the Social Sciences.

Effect of collaboration network structure on knowledge creation and technological performance: the case of biotechnology in Canada

Abstract: Many of the novel ideas that lead to scientific publications or yield technological advances are the result of collaborations among scientists or inventors. Although various aspects of collaboration networks have been examined, the impact of many network characteristics on knowledge creation and innovation production remains unclear due to the inconsistency of the conclusions from various research studies. One such network structure, called small world, has recently attracted much theoretical attention as it has been suggested that it can enhance the information transmission efficiency among the network actors. However, the existing empirical studies have failed to provide consistent results regarding the effect of small-world network properties on network performance in terms of its scientific and technological productivity. In this paper, using the data on 29 years of journal publications and patents in the field of biotechnology in Canada, the network of scientists' collaboration activities has been constructed based on their co-authorships in scientific articles. Various structural properties of this network have been measured and the relationships between the network structure and knowledge creation, and quantity and quality of technological performance have been examined. We found that the structure of the co-authorship network of Canadian biotechnology scientists has a significant effect on the knowledge and innovation production, but it produced no impact on the quality of patents generated by these scientists.

What do global university rankings really measure? The search for the X factor and the X entity

Abstract: Most academic rankings attempt to measure the quality of university education and research. However, previous studies that examine the most influential rankings conclude that the variables they use could be an epiphenomenon of an X factor that has little to do with quality. The aim of this study is to investigate the existence of this hidden factor or profile in the two most influential global university rankings in the world: the Academic Ranking of World Universities (ARWU) of the University of Shanghai Jiao Tong, and the Times Higher Education (THE) ranking. Results support the existence of an underlying entity profile, characterized by institutions normally from the US that enjoy a high reputation. Results also support the idea that rankings lack the capacity to assess university quality in all its complexity, and two strategies are suggested in relation to the vicious circle created between institutional reputation and rankings.

Erratum to: A hybrid keyword and patent class methodology for selecting relevant sets of patents for a technological field

Abstract: This paper presents a relatively simple, objective and repeatable method for selecting sets of patents that are representative of a specific technological domain. The methodology consists of using search terms to locate the most representative international and US patent classes and determines the overlap of those classes to arrive at the final set of patents. Five different technological fields (computed tomography, solar photovoltaics, wind turbines, electric capacitors, electrochemical batteries) are used to test and demonstrate the proposed method. Comparison against traditional keyword searches and individual patent class searches shows that the method presented in this paper can find a set of patents with more relevance and completeness and no more effort than the other two methods. Follow on procedures to potentially improve the relevancy and completeness for specific domains are also defined and demonstrated. The method is compared to an expertly selected set of patents for an economic domain, and is shown to not be a suitable replacement for that particular use case. The paper also considers potential uses for this methodology and the underlying techniques as well as limitations of the methodology.

The influence of scientific research output of academics on economic growth in South Africa: an autoregressive distributed lag (ARDL) application

Abstract: An increasing number of researchers have recently shown interest in the relationship between economic growth of a country and its research output, measured in scientometric indicators. The answer is not only of theoretical interest but it can also influence the specific policies aimed at the improvement of a country's research performance. Our paper focuses on this relationship. We argue that research output is a manifestation of the improvement of human capital in the economy. We examine this relationship specifically in South Africa for the period 1980---2008. Using the autoregressive distributed lag method, we investigate the relationship between GDP and the comparative research performance of the country in relation to the rest of the world (the share of South African papers compared to the rest of the world). The relationship is confirmed for individual fields of science (biology and biochemistry, chemistry, material sciences, physics, psychiatry and psychology). The results of this study indicate that in South Africa for the period 1980---2008 the comparative performance of the research output can be considered as a factor affecting the economic growth of the country. Similarly, the results confirm the results of Vinkler (2008) and Lee et al. (2011). In contrast, economic growth did not influence the research output of the country for the same period. Policy implications are also discussed.

Predicting author h-index using characteristics of the co-author network

Abstract: The objective of this work was to test the relationship between characteristics of an author's network of coauthors to identify which enhance the h-index. We randomly selected a sample of 238 authors from the Web of Science, calculated their h-index as well as the h-index of all co-authors from their h-index articles, and calculated an adjacency matrix where the relation between co-authors is the number of articles they published together. Our model was highly predictive of the variability in the h-index (R 2 = 0.69). Most of the variance was explained by number of co-authors. Other significant variables were those associated with highly productive co-authors. Contrary to our hypothesis, network structure as measured by components was not predictive. This analysis suggests that the highest h-index will be achieved by working with many co-authors, at least some with high h-indexes themselves. Little improvement in h-index is to be gained by structuring a co-author network to maintain separate research communities.

Are academics who publish more also more cited? Individual determinants of publication and citation records

Abstract: Thanks to a unique individual dataset of French academics in economics, we explain individual publication and citation records by gender and age, co-authorship patterns (average number of authors per article and size of the co-author network) and specialisation choices (percentage of output in each JEL code). The analysis is performed on both EconLit publication scores (adjusted for journal quality) and Google Scholar citation indexes, which allows us to present a broad picture of knowledge diffusion in economics. Citations are largely driven by publication records, which means that these two measures are partly substitutes, but citations are also substantially increased by larger research team size and co-author networks.