My citation count just went down!

May 26, 2012

We sometimes get angry emails from authors pointing out that their citation count decreased. And this is quite understandable, as no one likes to see decreasing citation numbers. But it can happen, and most of the time it is for very legitimate reasons, not some conspiracy. Here is a rundown.

  1. A citing or cited item has been removed from RePEc. This is rare but does happen on occasion. We recommend against removing item in general, as discussed in a previous blog post. Hint: the fact that a working paper got published in a journal is very rarely a reason to remove its link to full text, let alone its entire entry.
  2. A RePEc archive renumbers its handles. A handle is the identifier of every item in RePEc. It is supposed to be unique and permanent, yet every month some archive has the bright idea to renumber its material. The consequence: the citation analysis needs to be completely redone, and all the other links as well. This leads to a temporary decrease in citation numbers.
  3. When different versions of some work are linked, citations are consolidated. Thus what counted as separate citations now only counts as one. And this version consolidation can happen for the citing or the cited work.
  4. The author removed some work from the author profile, for example when a paper got published. Citations to the working paper version are then temporarily lost until the article is indexed in the citation service.
  5. An error with RePEc. This can happen despite our best efforts, and it always has been temporary.

And lastly, the citation count in the statistics sent to authors is different from what you see on the web at IDEAS or the RePEc Author Services: this is because multiple versions of the same work are aggregated, and because self-citations do not count.

On RePEc traffic numbers

May 19, 2012

RePEc provides traffic statistics to authors, editors, and archive and series maintainers. LogEc displays them to the public. These downloads and abstract views are obtained from some, but not all, RePEc services which compile their server log files: Economists Online, EconPapers, IDEAS, NEP and Socionet. The raw logs are purged from anything that does not look like human traffic (robots, spiders), repeat traffic as well as anything that does not seem licit. This typically divides traffic numbers by four or five. More details are available at LogEc.

Several people have noticed that RePEc traffic numbers have exhibited a downward trend over the last couple of years. We do not have a definite answer, but we have a few possible explanations for this trend.

Tightening of criteria

The criteria for what is considered licit traffic have been tightened in July 2010, retroactively to January 2008 (see blog post). This can explain a one-time decrease in reported traffic, but not the trend.

Server caches

We noticed that several institutions run server caches of IDEAS. This means that any request to an IDEAS page comes from this server, and thus requests from separate people count as one. Worse, if there are many such requests, the server is considered a robot and none count. While this has an impact on traffic numbers, it is not believed to be a major impact.

Proxy servers

These are servers through which all web traffic of an institution is routed. The main goal is security: all computers behind the proxy server appear to have the same IP address, and a potential attacker cannot find the individual IP addresses. The impact is the same as with the above: all traffic from an institution (for example the hundreds of economists from the US Federal Reserve System) are considered to be from a single person, and possibly a illicit robot. This can explain stagnating traffic and, if the adoption of proxy servers is increasing, even decreasing traffic.

Non-reporting RePEc services

Several RePEc services are not reporting traffic logs to LogEc. If they are diverting traffic away from reporting services, the visible statistics suffer. As RePEc is getting used more and more by bibliographic services, the declining recorded traffic gives then a false image of the evolution.

Google Scholar priorities

Substantial traffic is coming from Google Scholar, which used to rely substantially on RePEc for its initial launch, at least for economics material. As Google established partnerships with commercial publishers, commercial material is now privileged in search results and RePEc is often confined to the much less prominent “other versions.”

Better usage

It could also be that users are getting more efficient at finding what they are looking for, either because they are getting better at it, or because the RePEc services have improved their websites. If one needs to read fewer abstracts until one finds the right works, this will lower traffic and increase user satisfaction.

Reduced popularity

Finally, it could be also that RePEc services are becoming less popular, given the existence of several good alternatives (which are almost all using RePEc data). The fact that raw traffic, which includes all that LogEc eliminates, is still going up would invalidate this argument, unless this increase is entirely due to an increase in robot traffic.

All in all, we are not sure why we have the decrease in the “visible” traffic numbers. Maybe our loyal readers have further suggestions.

RePEc in April 2012

May 3, 2012

The innovation of the month is the complete overhaul of, the blog aggregator for economics research. It now monitors a much longer list of blogs and selects the blog posts that discuss research. Also, IDEAS now links back from the abstract and author pages to the posts.

We counted 634,507 file downloads and 2,319,912 abstract views during last month and welcomed the following new participating RePEc archives: Kasetsart University, Review of Agrarian Studies, Brigham Young University, Karl-Franzens-Universität Graz, Bahcesehir University, JICA Research Institute, La Trobe University (II), Western Risk and Insurance Association, IGI Global, Barcelona Graduate School of Economics, Universitatea Andrei Saguna, Scientific Society of Management from Romania, Duke University (II), and Università di Trieste.

Finally, we passed the following thresholds:
3000000 matched citations
2500000 cumulative downloads through NEP
2000000 cumulative abstract views for book chapters
700000 listed articles