What are the most cited recent papers in Economics?

December 22, 2007

RePEc has been publishing for several years now a list of the most cited papers and articles cataloged in its database according to three criteria, recently expanded to six. By popular demand, we now publish also a list of the most cited recent papers and articles. The selection criterion here is that the last know version has been published five or less years ago. That may sound like a long period, but considering the publication lags we suffer, I think it is reasonable. Thus, currently, articles (and papers) published in 2002 or thereafter qualify. Within a few days, those from 2002 will be dropped, so enjoy them while you can

At the same time, the list of the most cited items has been expanded. Previously, only the top 200 were released, now we show the top 1‰. This list thus gets longer as RePEc expands and stands currently at 559. Again, the list is available according to six different criteria. So, check out whether your favorite papers are listed. And remember, all this citation data is still experimental as we try to improve on its quality, but still quite informative.


15,000 authors on the RePEc Author Service

December 15, 2007

The 15,000th author registered recently on the RePEc Author Service (which also has another 5,000 registered, but without any works in their profile). See a list of all those registered at EconPapers or IDEAS. This give us the opportunity to reflect on the coverage of this service: what proportion of academic economists is covered? Let me offer a few suggestions.

Assume that the works listed in RePEc provide a representative sample of all the works written by economists. Then determine how many of these works are listed in the profile of a registered author. By that account, about 40.1% have been claimed, and thus about 40% of the profession would be registered with RePEc. This latter number is in reality higher, due to several biases: a) some authors are not alive and cannot register; b) some registered authors have the unfortunate habit to remove from their profile working papers once they are published; c) some works listed are not written by economists, and these authors are less likely to register with RePEc.

Alternatively, estimate the number of authors in the world from the membership in academic societies. I guess the three largest societies are the American Economic Association (18,000 members), the European Economic Association (2,300 members) and the Econometric Society (5,500 members). Obviously, their membership overlaps, and not every of their members is an author. But not every economist is member either. Assume that adding their membership numbers corrects for all mismeasurements, then the RePEc Author Service covers 58% of the profession.

One can also observe a specific subsample of economists, those listed among the top 1000 by Tom Coupé. There, the RePEc Author Service covers 75% of the top 1000 by publications and 65% of the top 1000 by citations (which includes quite a few non-economists). But we have good reasons to believe these proportions are higher than for the whole population. Indeed the proportion is significantly higher for the better ranked within this sample, and we can extrapolate that those outside the top 1000 are less represented in the RePEc Author Service.

In summary, the RePEc Author Service covers between 40% and 75% of the profession. Possibly less, possibly more, likely in between.


Blog disruption

December 14, 2007

The RePEc blog was offline for a few days due to a hardware failure, along with a few other websites at Boston College, our host. Everything seems to be running well now, but please contact us if you see any remaining issues.


The end of print journals?

December 8, 2007

The (US) Association of Research Libraries released a few days ago a report entitled “The E-only Tipping Point for Journals: What’s Ahead in the Print-to-Electronic Transition Zone” (pdf). It makes the argument that sooner or later every publisher will turn to an electronic-only format in the face of rising (relative) costs of print formats. Currently, we are in a transition period where most journals went from print-only to print and electronic, and it is predicted that with 5 to 10 years, the printed journals will be only from the most specialized and small ones who cannot afford the fix cost of setting up the electronic editions. Another feature of the transition is the large proportion of new journals that do not even bother with a print edition.

This discussion largely pertains to university press publishing, but can probably be extended to commercial publishing. Indeed, commercial publishers show signs that they want to discourage print editions, either through their subscription price structure or by modifying subscriptions to be by default electronic-only. In Economics, the dissemination of research, in terms of readership, is dominated by pre-prints (working or discussion papers) that have gone all electronic for some time now, with only few exceptions. As far as I know, nobody regrets the period of the all printed working papers: they were difficult to obtain unless you were in the “club”, only few institutions had a systematic (but costly) way to disseminate them, and only established researchers had any chance of being read through this medium. People would even travel to some libraries to consult their working paper collections. Today, research is much more widely disseminated and researchers from outside the elite institutions have a better chance to follow and contribute to the research frontier. We hope RePEc has contributed to this democratization. Never has been the use of electronic pre-prints as widespread as now, possibly at the cost of reducing journals to historical records of research. Well, journals also act as gateways through peer-review, but you sometimes have to wonder about this as well when hearing all the complaints about this process.

A few interesting numbers from the study: 60% of 20,000 per-reviewed journals are available in electronic format, library-provided electronic editions are at least ten times more read than print ones, only 30% of library subscriptions are print only.


Important changes in RePEc rankings

December 2, 2007

Two important changes regarding rankings:

  1. There are now rankings of authors and institution by field. As discussed before, the procedure is the following: identify relevant authors by the number of papers announced in NEP field reports. Past a threshold (currently 25% of all announced papers or 5 announced papers), the author is considered specialist of her field (see discussion. For institutions, each affiliated author contributes with a weight corresponding to the proportion of papers announced in the field, irrespective whether the threshold was met (see discussion).
  2. For rankings within regions (and within fields, described above), authors and institutions are not anymore ranked by picking them from the “grand list”, i. e., the ranking of all authors or institutions. Rather, the ranking is performed within the respective subgroup: for example, authors are ranked with the others of the same region according to all criteria, and then ranking points are aggregated. This had already been done a few months ago for women, which led complaints about this particular ranking to virtually disappear…

Soon, we will also add citation rankings for recent papers. An announcement will be made on this blog in a week or two. Note that all these rankings are experimental and subject to changes. We welcome discussions and suggestions about them in the comment section.


RePEc in November 2007

December 1, 2007

Every month, a short summary of what happened with RePEc is sent to the RePEc-announce mailing list. I will also put that message, slightly adapted, on this blog.

The new feature of the month has to do with rankings: There are now rankings of institutions and authors by field. Also, there have been procedural changes in the rankings within region. See the discussion of these items elsewhere on the blog.

We continue with fast paced additions of material. This year alone, over 100,000 items have been added to the bibliographical database. Accordingly, the RePEc web services are more popular than ever, establishing new traffic records: 697,596 file downloads and 2,516,310 abstract views within a month. This leads us to the thresholds we have passed this month:

2,500,000 abstract views in a single month
550,000 items listed
500,000 downloaded software components
325,000 articles listed
275,000 items with abstracts
225,000 papers listed
125,000 items with references
100,000 papers with references
90,000 articles with citations


Thanksgiving to Volunteers: Ivan Kurmanov

November 21, 2007

Ivan KurmanovAs the United States are celebrating Thanksgiving, it is time to celebrate our volunteers. With this post, we hope to start a regular feature that highlights the work that our volunteers do, sometimes unseen from the general public. RePEc is all built on volunteer effort, and we hope this feature will help these crucial people to get the recognition they deserve.

Today, we want to recognize Ivan Kurmanov, who has just left the RePEc team after being on board for over 10 years. As a undergraduate Economics major at the Belarussian State University in 1996, he noticed the work being led by Thomas Krichel at the now defunct NetEc, the precursor of RePEc. Thinking it was a great initiative, he volunteered to help out. Thomas quickly found something to get him busy: Writing ReDIF-perl, a perl module that validates the data contributed to RePEc by the participating archives and then massages the data for uses by RePEc services. ReDIF-perl has proven to be tremendously useful. Then, Ivan tackled the RePEc Author Service (then called HoPEc) that needed a lot of work, especially to iron out various bugs and performance issues. This was no easy task, as HoPEc was programmed in C++, while all other components of RePEc run with perl. Eventually, it became clear that a complete code rewrite became necessary.

Thomas managed to find a grant from the Open Society Institute to provide an open source author registration system, and Ivan started working full time on it. This is how the current RePEc Author Service was created, based on ACIS, which is now open source under a GPL license. ACIS performs quite complicated tasks, like pattern matching of names, which may include accents and other marks, or citation analysis with surprising efficiency. Another remarkable aspect of this project is that it is extremely well documented, unlike many other RePEc projects, unfortunately.

While technically Ivan was paid for part of his time with RePEc, we should still consider him a volunteer given all the tremendous work he has performed that went well beyond what would have been expected from the little money the grant provided. Also, he had to cope with often shaky Internet connections in Belarus. Ivan now works full time as a programmer, and we hope he will still listen in on RePEc and give his advice, and occasional fixes. Of course he leaves a void, and while Thomas Krichel is currently providing interim coverage, we are looking for a new volunteer to maintain and expand the code behind ACIS and the RePEc Author Service.


More on peer review and blogging

November 15, 2007

A community of research bloggers tired of being confused with “news, politics, family, bagpipes, and so on” blogs has started its own blog at BPR3 (Bloggers for Peer-Reviewed Research Reporting). The idea is to encourage peer review bloggers to certify themselves and use an icon on their blog. We discussed earlier whether such blogs would be appropriate in Economics, along with some past experiences. Other fields seem to have some active research blogs. Do we have any blog in Economics that would qualify?

Inside HigherEd has two articles on academic blogging, one discussing how painful it is, the other how great it is. Both authors are graduate students, but they can still offer interesting perspectives to more seasoned researchers tempted by academic blogging. A few excerpts:

Over the past three years, I’ve learned what it’s like to write in a way most academics never have: namely, for an audience. If this seems like a simple point, that’s because it is. Nor is it one of those profoundly simple points, either: it’s straight simple. When a blogger sits down to slave on her dissertation, article, or book, she doesn’t turn her back on the public sphere. Because in the end, the public sphere is us.

I’m talking about the communities we currently have, only five years in the future, when we’re scattered around the country, unable to communicate face-to-face, but still connected, still intellectually intimate, because we’ll still regularly be engaged with each other’s thoughts. But I’m not only talking about us. There’s no reason our community needs to consist solely of people we knew in grad school. Why not write for people who don’t already how you think about everything? Why not force yourself to articulate your points in such a way that strangers could come to know your thought as intimately as your friends from grad school do?

More than formatting issues, however, I think that everyone needs to realize that having a productive conversation in an online format is very hard work, which is why it happens so rarely. Many bloggers can point out online conversations in which they were pushed to think in a new direction or got genuinely valuable feedback on a question, but as with all human endeavors, there is a high percentage of dross to go along with the occasional gold. Policing comments is a difficult job, and efforts to keep conversations on-topic or ensure that contributors have some substantial knowledge to share will often cause resentment in light of the “democratic” leanings of online communities. All this is on top of the obvious problems with online interaction as opposed to in-person conversations.

As more and more academic resources become available online, hopefully academic blogs will begin to fill a role analogous to the political blogs that link to and comment on particular news stories — that is, bringing new scholarly research to the attention of an interdisciplinary audience. I hope that events like this will help to push more journals toward open-access electronic formats. Failing that, however, academic blogs seem to me to be best-suited as a social outlet for academics who would otherwise feel isolated, creating camaraderie and supplementing the social aspects of disciplinary conferences.

There is also a discussion on this topic on the blog of the Association of College & Research Libraries.

The RePEc blog does not consider itself to be part of the research blog community, indeed our focus is not research but the dissemination of research. Hence, we are interested in understanding the feasibility and the interest in research blogs in Economics. And if any research blogs appear (or already exist) in Economics, RePEc would be more than happy to feature them on this blog and possibly elsewhere.


Ranking Institutions Within Fields

November 9, 2007

In previous posts, we discussed how to categorize authors by field and then how to rank them within fields. These discussions are still open and I can still be convinced to change the procedure. Today, I would like to make a proposal regarding the ranking of institutions within fields.

We have several options regarding how to count people from an institution for a specific field. In the examples, I assume that author A has 10, or 50%, of his works in macroeconomics, B 3 or 30%, C 10 or 20%, D 1 or 10% and A 0%. I also assume that the 25% and 5 rule applies, as discussed in the post on categorizing authors. Thus, under these rules, authors A, B, and C are considered macroeconomists. The options are:

  1. Count fully all authors considered within the field: A+B+C.
  2. Count all authors considered within the field proportionally to their involvement in the field: 0.5A+0.3B+0.2C.
  3. Count all authors, irrespective whether they qualify as specialists, proportionally to their involvement in the field: 0.5A+0.3B+0.2C+0.1D.

My preference is for option 3. The reasons are the following. The first option fails to properly differentiate between strong specialists and marginal ones. This may also have been a concern when ranking authors, but the issue there was the high volatility of weights at the author level. At the institutional level, this is less of a concern as several authors are aggregated. Note also that only the top 20% institutions will be listed anyway, thus I expect all of them to have several authors within the field. Thus I prefer option 3 over option 1. Then I prefer option 3 over option 2 because it allows to count for authors that may not be specialists but still may contribute to enriching the field. Think for example when a prospective graduate student compares programs. While she cares about the specialists of her field of interest, she may also care about those faculty on the fringes of the field.

Of course I am open to suggestions and can still be swayed to to change my opinion. I plan on implementing this for next month.


Ranking Authors Within Fields

November 4, 2007

As discussed earlier on this blog, we are trying to categorize authors by fields. The current proposal is to consider someone in a field if either 5 or 25% of her papers announced in NEP where announced in the relevant field report. These parameters are still open for debate, and the reader is welcome to weigh in. Once this is done, the next step is use this methodology to rank authors within fields. There are several ways in which this can be done.

  1. Take the unweighted list of authors in each field. This means the following: Take the list of authors as categorized by the parameters mentioned above. Just rank them within the list assuming the same weight to each.
  2. Do the same, but with weights. Those weights would correspond to the share of the field within each author’s work. So an author who has 4 of 12 papers announced in NEP announced in the NEP-MAC report would have one third of his scores count towards the ranking among macroeconomists.
  3. Do the same, but not restrict to those have passed the threshold to qualify for a field (currently 5 papers or 25% of papers announced in NEP).

My preference would go for the first option. I do not think that the field weights are that precise to allow using them for authors. Also, the ranking of author in a field may drop with the other options for the sole reason that he has published a working paper in another field.

I intend to have the first field rankings available in a month, so voice your opinion before then.