RePEc in May 2010

June 6, 2010

May was a rather unusual month. Traffic has be lighter than usual, with 751,319 file downloads and 2,512,833 abstract views, but a large number of bibliographic items were added to RePEc, about 14,000. At this pace, we should be reaching a million within the year!

Also, 12 new archives joined RePEc: Swiss Economics, National Bank of Serbia, Toulouse School of Economics, University of Copenhaguen (II), Universität Basel, US Department of Justice, Kasetsart University, Center for Strategic Research and Analysis, Institutul de Economie Mondiala, University of Warwick (III), Universität Münster (II) and the European Commission (II).

Finally, these are the thresholds we passed during this past month:
1000000 book abstract views
550000 listed articles
400000 book chapter downloads
250000 articles with abstracts
24000 registered authors
12000 online chapters


Improving metadata

May 21, 2010

The bibliographic data used by RePEc services can only be as good as what publishers provide. While a post last month discussed how to improve citation coverage, the present one gives some advice to RePEc archive maintainers on how to improve their metadata to optimize their use in RePEc services. For starters, here is how a well formed RePEc template would look like:

Template-Type: ReDIF-Paper 1.0
Author-Name: Daniel Rais
Author-Name: Peter Lawater
Author-Email: p.lawater@grandiose.edu
Author-Workplace-Name: Department of Economics, Grandiose University
Author-Name: Jonathan Goldman
Author-Workplace-Name: Department of Finance, Grandiose University
Author-Name: Zhiwei Chui
Title: Phases of Imitation and Innovation in a North-South Endogenous Growth Model
Abstract: In this paper, we develop a North-South endogenous growth model to examine three phases of development in the South: imitation of Northern products, imitation and innovation and finally, innovation only. In particular, the model has the features of catching up (and potentially overtaking) which are of particular relevance to the Pacific Rim economies. We show that the possible equilibria depend on cross-country assimilation effects and the ease of imitation. We then apply the model to analyze the impact of R&D subsidies. There are some clear global policy implications which emerge from our analysis. Firstly, because subsidies to Southern innovation benefit the North as well, it is beneficial to the North to pay for some of these subsidies. Secondly, because the ability of the South to assimilate Northern knowledge and innovate depends on Southern skills levels, the consequent spillover benefits on growth make the subsidizing of Southern education by the North particularly attractive.
Length: 26 pages
Creation-Date: 1996-07
Revision-Date: 1998-01
Publication-Status: Published in Review of Economics, March 1999, pages 1-23
File-URL: ftp://ftp.grandiose.edu/pub/econ/WorkingPapers/surrec9602.pdf
File-Format: Application/pdf
File-Function: First version, 1996
File-URL: ftp://ftp.grandiose.edu/pub/econ/WorkingPapers/surrec9602R.pdf
File-Format: Application/pdf
File-Function: Revised version, 1998
Number: 9602
Classification-JEL: E32, R10
Keywords: North-South, growth model, innovation assimilation
Handle: RePEc:aaa:wpaper:9602

This is just an example, and there are more fields that can be used. See the step-by-step instructions for opening a RePEc archive for much more details. But let me point out a few recommendations:


  1. The more fields are filled, the better it is. But these fields must be legal, as defined in the documentation, or the entire template is rejected.
  2. One put information relevant to a field. For example, there should be no affiliation in the Author-Name:, or no paper number in Title:.
  3. The Author-Name field should contain only one author. Repeat the field for multiple authors! This is important, other wise we have difficulties attributing papers to authors on the RePEc Author Service.
  4. If there are multiple versions of a paper within the same series, repeat the File-* block as in the example above instead of creating a new tempate.
  5. Handle is a unique identifier that should not be changed, and in particular that should not be recycled. The latter point is very important, as handles provide links between papers, authors, references, citations, statistics, etc. Handle recycling introduces errors that are very, very cumbersome to correct.
  6. Do not confuse fields. Too often, an abstract is put in Title:.
  7. If you are not sure, check your template here.
  8. And check your monthly emails for any errors we may have detected, or check your archive here. There is even a URL checker to help your work!


RePEc is not a spider

May 13, 2010

We frequently get requests for inclusions in RePEc, and often these are complaints that some papers on a university department web page or a personal home page are not being picked up. RePEc is not Google. RePEc does not have a web spider that wanders the web and looks for research in Economics. I do not even think it would be possible to do so, as identifying research and Economics on an automatic basis is very difficult.

Material listed on RePEc is submitted, either by about 1200 participating archives, that each have followed our instructions, or by authors themselves at the Munich Personal RePEc Archive (MPRA). No need to send us links or papers. Just make sure your publisher participates, and if not upload your papers at MPRA (what you can in general also do for published material, see this previous blog entry).

And if you are really interested in a web spider for Economics, there is the Economic Search Engine (ESE), which uses in part RePEc data to search and index the subset of the web most likely related to Economics.


RePEc in April 2010

May 5, 2010

April has been a memorable month, with close to 40,000 works newly indexed. We thus reached 900,000 index works, of which 750,000 are online. Also, we have now counted 200 millions abstract views since the start of the project, a highly filtered number as the raw count before removing multiple views, robots and other “illegal” activity is four times that.

The 13 new archives that joined RePEc in April were: Chapman University, Africa Growth Institute, Università Cattolica del Sacro Cuore (II), Programme National Persée, United Nations Development Programme, University of Winnipeg, University of Valencia (III), Leuphana University Lüneburg, Revista de Economía Crítica, Università Roma 1 (III), University of California-Davis, Pontifica Universidad Católica de Perú, Università Roma 2 (II).

And, finally, we reached an impressive list of thresholds during the month:
200,000,000 cumulative abstract views
900,000 listed works
750,000 listed online works
500,000 abstracts
24,000 registered authors
3,000 online books


How to improve citation coverage in RePEc

April 28, 2010

One aspect of RePEc that has grown in importance over the last years is its citations analysis, provided by the CitEc project, in particular due to their use in rankings. Citations extractions is a complex process. First, one needs to be able to access texts and find where references are (see details), then one needs to be able to interpret those references and match them with some work already listed in RePEc (see details). At this time, 5,400,000 references could be extracted from 240,000 works, with 2,300,000 matched to an item listed in RePEc. While these numbers may sound impressive, it still means that only about a third of online texts could be parsed successfully. To improve on this we rely on the RePEc archive maintainers to help us do a better job. Here is some advice in this regard that they should heed, as any linked reference allows links back and forth between the citing and cited works, thus increasing visibility.


  1. Check out how successful CitEc is in extracting references from your series and journals. Maintainers receive every months statistics about coverage that they can monitor. In addition, they can look up on CitEc the reasons why some items were not processed. For the series with the best coverage, see here.
  2. Make sure links in the metadata go directly to a pdf file, and not to an intermediate abstract page. CitEc does not go further than the link that is provided to it. If you really want the abstract page present in the metadata, provide it as a second link.
  3. Make sure that CitEc is actually allowed to get to the pdf. If the pdfs are gated, consider allowing CitEc to access with its IP, which will be provided upon request.
  4. The above are not possible, or if for some other reason references cannot be parsed, one can also transfer references to CitEc by using the X-File-Ref construct in the metadata, as described here.
  5. For larger archives, an alternative way of transferring references can be arranged.
  6. Also, CitEc sometimes grabs too many references. This happens for working papers when a list of other papers in the series is appended. This is also a waste of paper. We strongly recommend not to have such lists and, where they are present, to alert CitEc so that these errors can be remedied.

Any request should be send to José Manuel Barrueco, who is in charge of the CitEc project.


Volunteer appreciation: Christian Calmès

April 19, 2010

RePEc relies completely on volunteer work, and some of them do work that is invisible from the outside. One of those is Christian Calmès, Associate Professor of Economics at the Université du Québec en Outaouais (Canada) and the “enforcer” on NEP. NEP is a collection of mailing lists that distribute announcements of new working papers in currently 87 fields. Those announcements are vetted by volunteers editors, who decide which papers are relevant for their fields. Subscribers expect to receive timely messages about once a week, and Calmès makes sure editors do their job. If necessary, he relieves them of their duties (after some warning). On occasion, this has meant that he had to take over managing a list, in the absence of an available volunteer. Currently, he manages NEP-BEC (Business Economics), NEP-BAN (Banking) and NEP-REG (Regulation).


Using RePEc as a search tool

April 11, 2010

Different people experience RePEc through its different uses, sometimes without being aware of its other uses. The purpose of this post is to highlight the use of RePEc services for bibliographic searches.

Currently, there are three different websites that offer bibliographic searches based on the data collected by RePEc: EconPapers, IDEAS and EconomistsOnline. Why use them instead of simply Google or Google Scholar? First, RePEc services allow fielded search: given the structure of the underlying metadata, it is possible to separate search results by authors, topical area, date, publication type and other attributes. EconomistOnline goes here the furthest, by allowing to narrow result sets successively according to various criteria. Second, the database and the search engines are updated as soon as publishers post new material, thus search results always reflect current holdings. Finally, as RePEc is not a spider, rather a catalog indexed directly by publishers, contents are known to be related to research in Economics. Thus, there are no irrelevant search results.

In addition, there are plug-ins available for most popular browsers both EconPapers and IDEAS. They allow to search RePEc directly from the search bar in a browser.


RePEc in March 2010

April 3, 2010

Last month, participating RePEc services counted 1,001,805 file downloads and 3,425,056 abstract views. Yes, for the first time, we have over a million downloads within a month. This was achieved with record traffic at IDEAS and NEP. In particular, there have been now 150 million abstract views on IDEAS since this was counted.

We have welcomed 16 new archives: Competition Policy International, University of Maribor, Czech Econometric Society, European Bank for Reconstruction and Development, EduSoft Publishing, Keio/Kyoto Joint Global COE Program, Polish Ministry of Finance, European Research Studies Journal, Feng Chia University, Osteuropa-Institut, Università Sapienza (II), Temple University, Université de Poitiers, Associazione Paolo Sylos Labini, St. Petersburg State University, Turkish Banking Regulation and Supervision Agency.

Finally, these are the thresholds we passed last month:
1,000,000 monthly downloads
500,000 items claimed in author profiles
450,000 online articles listed
12,000 book chapters listed
7,000 books listed
2,500 online books listed


RePEc rankings: adjustments and novelties

March 26, 2010

Given the increased interest in the various RePEc rankings, as well as thanks to comments made by users, I have made various adjustments over the last months. Some are barely perceptible, while some give some new features. Here is a short list.


Aggregate ranking for series and journals
Thanks to popular demand, there is now a ranking that aggregates the four impact factors, the h-index, download counts and abstract views. This ranking is available for journals, working paper series and all series.
Linked series
By linked series, I mean the situation where a series ceased to exist and continues under a new name. This happens in particular for journals that switch publishers, or journals that merge. Various statistics are now merged for ranking purposes. Thus, there is now a unique impact factor for the various series or journals. This was more complex to pursue for the h-index, and obviously all affected series gained from that. However, this increased the scope of self-citations that could be removed for the impact factor calculations.
Note to RePEc archive maintainers: you can link your series or journals to others by adding a new field in your series templates, Followup: or Successor:, followed by the handle of the other series.
Expanded listings
Following a poll a few months ago, the portion of the rankings that is public has been expanded. This will be visible with the ranking released early next month. The ranking of authors and institutions within countries or US states passes from the top 20% to the top 25%, within fields from the top 5% to 10%. The big ones, the top 5% authors and institutions still includes the top 5% in much detail, but now also the next 5% in five 1% “bins.”
US Economics departments
While there is already a ranking of Economics departments, one of the most frequent requests is to have one specifically for the United States. There will be one starting with next month’s update. Link.
Lost authors
We sometimes lose track of some authors when their monthly messages bounce back. Typically this is because they have moved or died. In both cases, they should not be counting towards the ranking of the institutions they are affiliated with. For a few months now, they have not. By the way, you can help rectify their status or their address by alerting us. The list of lost authors is here. See also the known deceased authors.
Peer authors
Registered authors receive every month an email with an analysis of their rankings. This now also includes a list of about 20 peers that are similarly ranked.
Errata
There is no reason an erratum or a correction should count as an additional publication for an author. We now try to drop them from ranking considerations and also to link them to the original article.


Volunteer appreciation: Volker Schallehn

March 15, 2010

Volker Schallehn is librarian at the University of Munich, but not your normal librarian. He has always been very active in open access, the free dissemination of research. For example, he has set up the institutional archive for the University of Munich, now one of the larger ones in the world, and doing so got so familiar with EPrints that he contributed code to this open-source project, along with a German translation of its interface.

His involvement with RePEc started when we were looking for a successor to the Economics WPA, which was holding papers for authors whose institutions or publishers were not (yet) participating in RePEc. Ekkehart Schlicht had the idea to add another repository to those Volker was already managing, hoping to exploit returns to scale. Volker agreed, seeing the broader mission in this initiative. Thus in 2006, the Munich Personal RePEc Archive was born, which now houses over 11,000 works and continues to grow steadfastly.