RePEc in August 2009

September 3, 2009

The quietest month of the year still brought some important news. RePEc now carries bibliographic information about 1000 journals and 300′000 working papers. We counted 647,942 file downloads and 2,213,814 abstract views for the month. For working papers, this adds up to 25 million downloads since we started counting!

In terms of developments, the RePEc Input Service now also allows journals that for some reason cannot open their own RePEc archive to index their articles in RePEc. Also, EconPapers allows users to download bibliographic data in various formats for their own databases. Both developments are due to Sune Karlsson, who also moved EconPapers and LogEc to new hardware.

During August 2009, the following archives joined RePEc: Sam Houston State University, arXiv, National Insurance Institute of Israel, University of Rome Sapienza (II), Economic Research Institute for ASEAN and East Asia, EPFL (II), BBVA, Journal of Transport Economics and Policy, Queens University of Charlotte. A special mention regarding arXiv: it is a very large and popular archive in Physics, Mathematics and Computer Sciences that is now feeding its Quantitative Finance content to RePEc.

Finally, here is the traditional list of thresholds passed during the last month:
25,000,000 cumulative working paper downloads
300,000 working papers
150,000 working papers with references
60,000 articles with references
1,000 journals


MPRA, the Munich Personal RePEc Archive

August 27, 2009

The Munich Personal RePEc Archive (MPRA) has been started three years ago. It has developed into one of the largest archives within the RePEc network, comprising roughly 9000 items at the time of writing. Christian Zimmermann has suggested that I share some toughs about its history and functioning.

The initial idea occurred to me when I heard that the Economics Working Paper Archive (EconWPA), run by Bob Parks, was discontinued in 2005. EconWPA offered the possibility for individual authors to make their contributions accessible to the community through the RePEc network, given that only institutions can set up RePEc archives. Although we have in Munich our discussion paper series integrated into RePEc, not all economists are so fortunate, and the need for a personal archive (as distinct from an institutional archive) was apparent.

Given that we had successfully established our department’s discussion paper series with the EPrints software, it appeared technically feasible to clone the software and use it for a personal RePEc archive. Discussion on the internal RePEc list led to the name “Munich Personal RePEc Archive,” the main concern being to clarify that the archive was intended as a RePEc service, rather something  original, and that the name would not exclude other personal RePEc archives in other locations. (If one of the other Munich universities wants to start another personal archive, we may get into a problem…)

I asked Volker Schallehn from the University Library, who has implemented the EPrints software for our university archives, about the possibility to help with such a project. He agreed to help. The next step was to convince the president of the university as well as the director of the library to agree dedicating some resources to the endeavor that would not serve people from Munich at all. They were in favor, and so we got started on September 19, 2006.

From a technical point of view the main problem was to automatize as much as possible, as we could not supply manpower: The generation of title pages, the  creation of metadate in the ReDif format required by the RePEc harvester, and the linking to the RePEc author service. With the help of  Thomas Krichel, Christian Zimmermann, Kit Baum, Sune Karlsson, Ivan Kurmarov, and others we manged to solve these problems and set up the website. We found editors. They do the main job now. The English editors handle often more than 50 submissions per day.

As the Eprints software permits to establish series in different languages, we decided to use these feature and to offer the service in all languages for authors who deal with country-specific issues and want to make their research available in their local language. However we require for all submissions English abstracts such that all users can obtain an impression what economists writing in other languages do and, if necessary, contact them. This feature has lead to quite a number of submissions in languages like Spanish or French, and to some smaller sets in Turkish, Arabic, and others. (Some of them look extremely pretty.) Maybe this feature creates a sense that all economists world-wide see themselves as members of a community with the common purpose of helping to improve living conditions around the globe.

A central motivation for establishing a pre-print archive like MPRA was to enable authors to secure the copyrights for their pre-print versions in case the copyright for the final article goes to the publisher. This permits open access to their work, even if publishers try to make the final work inaccessible for the non-paying public. This is a great convenience for academics and, I hope, generates a countervailing power that keeps a check on journal prices. Further, this arrangement provides a means for the authors to make their work accessible to others through the RePEc services.

As an unintended by-product some authors have obtained requests from publishers to publish their contribution in a volume or journal. This may indicate a trend for the future: While authors submitted their works to publishers (and paid for it), in the future simply put your stuff on the net, and publishers approach you in order to create collections that generate value added beyond mere publication, such that people and libraries a willing to pay for it. If MPRA could contribute to such a development, this would be nice.

It is quite astonishing to me how many good papers we obtain, in spite of the fact that we do no refereeing at all. (The editors check only some formal aspects, making sure that the submission is of academic nature, and a certain convention has emerged in this respect.)

MPRA offers a public forum for publishing papers, but not only that: It offers the possibility to publish comments on papers in the archive. This feature is not used. Maybe somebody has a suggestion how to organize discussions around papers such that people actually feel inclined to use such a feature.

So much about MPRA. If you have any suggestions, please feel free to communicate and discuss them on this blog.


On versioning in RePEc

August 21, 2009

RePEc carries research in various formats. While journal articles are unique (with very few exceptions), working papers, as they are pre-prints, may be duplicates of listed articles, and they may even appear in different versions, either because they are published in different series, or because there may be updates within a series. We believe that is important to carry all versions, not just the last one, for the following reasons.


  1. Time-stamps: A working paper allows to establish when some research was conducted and thus determines preeminence of research ideas. Given publication delays in Economics, this can be important.
  2. Open access: Many journal articles have gated access. Such restrictions can be bypassed by reading working papers, which are mostly open access.
  3. Link to published version: It is still preferred to use published versions in citations, especially once a paper is accepted in a journal. The originally cited working paper is often linked to its published version.
  4. Visibility: Working papers are much more read than journal articles, both because they are more current and they are freely available. In addition, working papers are disseminated through NEP.

The process of linking the various versions of the same work is not obvious, however. With about 800,000 works in RePEc, performing matches on titles is a daunting task, especially as fuzzy matching is necessary due to slight variations in punctuation and spelling. For this reason, we do the matching only across the works listed in an author’s profile. This ensures that the likelihood of two works being different versions of the same one to be very close to 100%. But this also means that such matching cannot be done for works where none of the authors is registered, or where a registered authors did not add all versions to the profile, thereby indicating he/she is not the author of this particular version, rightly of wrongly.

In some cases, titles change across versions, or journal editors require a title change. In such cases, a manual link between versions can be added, just contact a member of the RePEc team with the relevant RePEc handles.


EconPapers and LogEc on new hardware

August 12, 2009

Thanks to the continued support of the Swedish Business School at Örebro University, EconPapers and LogEc are now running on new and upgraded hardware. This will allow for the smooth running of these services over the next few years as the coverage of RePEc continues to grow and new features are added to the services.

EconPapers is a website that displays all the bibliographic data collected through RePEc. Contents can be browsed in various ways. A powerful search engine is also available. LogEc collects and displays statistics about abstract views and downloads from EconPapers and other participating RePEc services. Both EconPapers and LogEc are run by Sune Karlsson.


RePEc in July 2009

August 4, 2009

The month of July is generally calm. Regular classes are not in session on campuses, researchers are on vacation or at conferences, thus it is to be expected that RePEc sees little new material or traffic. We counted 674,639 File downloads and 2,287,995 abstract views, relatively modest numbers, saw only six new archives: Universidad de los Andes, Katholieke Universiteit Leuven (II), Spiru Haret University Brasov, Austrian Academy of Sciences, ETH Zürich (III), German Council for Social and Economic Data. The first added Venezuela to our list of participating countries, which is now at 68.

We still managed to pass a few thresholds:

400000 online articles
12500 listed book chapters
5000 subscribers to NEP-HIS, the largest subscriber base in NEP


Volunteer recognition: Bernardo Batiz-Lazo

July 31, 2009

Bernardo Batiz-Lazo is a business historian with a deep interest in the dissemination of research. Quite naturally he became editor of NEP-HIS and quickly, in 2000, took the responsibility for the whole NEP project until 2007. He is still very much involved, still editing NEP-HIS, which is the mailing list with the most subscribers, at now over 5000. Occasionally, he has also edited other NEP reports on an interim basis.

Under Bernardo’s auspices, NEP grew tremendously. First, he made sure that every field of economics and some fields in business are covered by NEP. In principle now, every new working paper in RePEc should be picked up by at least one NEP report and announced by email and RSS. This required a substantial recruitment effort of new volunteer editors, complicated by the fact that new fields needed to be covered. Bernardo also worked hard to increase the subscriber base, not because it would increase revenue (there is none), but because of the network effects that make it more worthwhile to post papers on RePEc, and thus subscribe to NEP, etc.

While Bernardo retired from NEP leadership duties (taken over by Marco Novarese), he is still very active in the RePEc community, both in internal discussion and with NEP-HIS.


About RePEc impact factors

July 27, 2009

Impact factors have always been a popular way to measure the influence of academic journals. They have been popularized by ISI, now part of Thomson. RePEc also provides impact factors, and this post is about explaining the differences between the two.

ISI takes a sample of journals and analyzes the citations across those journals. To be eligible, a citations has to appear within two years of the publication of the cited article, the cited article must be printed (not forthcoming, a working paper or a manuscript), and the cited article must be among the analyzed journals (286 in Economics). ISI is currently experimenting with a five year window, in addition to the existing two-year window.

RePEc considers all publications listed in its bibliographic database. Thus, it also considers other publication forms than journal articles: close to 1000 journals and 2600 working paper series. It imposes no time window, citations of any age qualify. In most cases, a citation of a working paper will count towards its published form once the article is included in RePEc, possibly after the original citation (condition: at least one author has both versions in his/her RePEc profile). This implies that working paper series and book series can also have impact factors. RePEc is thus more comprehensive.

However, the pool of citations RePEc is drawing from is different. It relies very much on working papers (who can later be published), as they are typically openly accessible. Some publishers also provide references in the bibliographic metadata, but not all. One implication of this is that RePEc is more current as it includes citations to and from research that is not yet published. As research gets published, this data gets updated. But as references from many journals are missing, RePEc citation data must still be treated as experimental. Whether these omissions matter remain to be seen. After all, impact factors always have to be considered in relative terms, not in absolute terms, and if omissions were not biased, they would not matter.

Another major difference is that RePEc excludes self-citations. This is an important issue as some journals, explicitly or implicitly, encourage authors to cite other articles published within the two year window in the same journal. Thus, just as self-citations are excluded for authors, they are excluded for journals. And this can matter a lot.

Finally, the impact factor is determined by divided the eligible citations by the number of eligible articles. ISI determines itself what articles are eligible for the denominator, and this can even be negotiated with the publisher. In RePEc’s case, if an article (or a working paper) is listed, it counts without adjustment.

RePEc also publishes variations on the “simple” impact factor: recursive impact factors, where every citation counts with the impact factor of the citing publication, this favors impact over numbers; discounted impact factors, where the impact of a citation decays with time (regardless of the age of the cited item; and a combination of the two, discounted recursive impact factors. Finally, there is now also the h-index. All variations have a different story to tell about the publication, and RePEc offers the reader the choice.


Moving time is time to update RePEc data

July 19, 2009

Summer is when most academics move to new affiliations or responsibilities. It is thus a good time to detail what needs to be done for RePEc data to remain accurate. There are close to 30′000 contact details listed in RePEc, yet only 466 have expired email addresses. You can help keeping this list short.

Registered authors

If your email address changes, log in at the RePEc Author Service with your old address, then click on “Contact details” to amend your email address and any other contact details. Note: do not create a new account with your new email address. This would create a duplicate, and then links to and from your profile would disappear once the old account is deleted. Remember also to amend your affiliation(s) if necessary.

Note that starting next month, authors with obsolete email addresses will not count towards their affiliation’s ranking. This is under the assumption that if the email address is not valid anymore, it must be because they have moved.

RePEc archive and series maintainers

If your email address is changing, or if there is a new person in charge, amend your series and/or archive templates. These are the *seri.rdf and *arch.rdf files in the root of your archive. There is no need to email us, as we extract from your templates the addresses for the monthly emails. However, if your RePEc archive moves to a new location, we obviously need to know about it.

Editors

Editor data is provided at two locations: by the RePEc Author Service and by the relevant publishers. In the first case, an email address change is handled as for a registered author. If you are not an editor anymore (and your editorship is listed in your RePEc profile), you can remove this by logging in at the RePEc Author Service: click on “Research” then “identified”, check your old journal, and approve the removal. To add a journal you now edit to your RePEc profile, either look at the suggested research items (if your publisher put in your name in the RePEc data), or do a manual search with the journal title.

Your publisher may also provide directly your name and your email address to RePEc. Your can see this on the listing of your journal on EconPapers or IDEAS. There you see also a technical contact. This is where you need to email to request a change in the listing.


RePEc in June 2009

July 10, 2009

What’s up at RePEc? We are happy to see an ever increasing popularity of our services, which has manifested itself last month with a record number of newly participating archives, 26, or one every working day: Univesidad de San Andres, Universität Marburg (II), Intervention, University of Florence (II), Bucharest University of Economics (III), University of Warsaw, Lucian Blaga University, University of Queensland (II), Universidade Federal de Goias, Banque de France, National Bank of Poland, Griffith University, University of Malaya, Associazione Rossi Doria, Superintendencia de Valores y Seguros, Basque Institute of Competitiveness, Bancaria, Jerusalem Institute for Market Studies, University of Buckingham Press, Sacred Heart University, Cahiers d’Économie Politique, Universidad Nacional de La Plata, University of California Riverside, Osaka University, Asociación Española de Historia Económica, Red Iberoamericana de Economía Ecológica.

In terms of traffice, we counted 725,569 file downloads and 2,588,500 abstract views. This allowed us to break the mark of 40 million downloads since we started counting this. As usual, many details are available at LogEc.

In terms of thresholds, we are proud to announce the following for June 2009:

60,000,000 article abstract views
40,000,000 downloads
15,000,000 article downloads
650,000 items available online
450,000 listed journal articles
250,000 book chapter downloads
10,000 listed book chapters
10,000 online book chapters


RePEc coverage outside of academia

June 29, 2009

RePEc indexes research in Economics, and one usually thinks about publications in journals and pre-prints disseminated by universities through the form of working papers or discussion papers. The fact is that a lot of research is also conducted outside these institutions. Take as an example central banks. Beyond their role of managing the money supply in their respective countries, as well as in some cases operating the payment system and regulating parts of the financial system, they conduct research to facilitate their operations and more generally understand the economy.

Much of this research is also present on RePEc. The following central bank have opened RePEc archives: Australia, Austria, Belgium, Brazil, Canada, Chile, Colombia, Cyprus, Czech Republic, England, France, Greece, Hong Kong, Hungary, Iceland, Ireland, Italy, Japan, Latvia, Lithuania, Luxembourg, Mexico, Netherlands, New Zealand, Norway, Peru, Poland, Spain, Turkey, United States (all Federal Reserve Banks). The following participate through an aggregator: Finland, Germany, Sweden, Switzerland. And finally, the following supranational institutions have a RePEc archive: Bank for International Settlements, European Central Bank, International Monetary Fund. There are plenty of other governmental institutions participating as well, in particular statistical offices, ministries and regulators.