This document contains a detailed description of the way that we calculated statistics reported on journalprices.com. The database may be updated at any time with revisions or corrections. Please contact the website owner with any questions.
This edition of journalprices.com is based on prices for institutional subscriptions for the year 2010 and on citations and article counts for the years 2004-2008 as reported by the ISI Journal Citation Reports. We include data for 8,422 journals as compared to 7005 journals in the previous edition. We have included all journals from which the ISI Web of Science publishes citation counts and for which we were able to find prices. Occasionally journals change names and/or ISSN numbers. For such journals, citation counts may be underestimated. The previous edition of journalprices.com covered 7005 journals. Information about most of the newly listed journals is available because the 2009 version of the Web of Science has added approximately 1500 journals from which it previously did not collect citation information. The prices listed in this edition of journalprices.com are 2010 institutional subscription prices. The citation and article counts are for the years 2004-2008 as reported by the ISI Journal Citation Reports. We have included all journals from which the ISI Web of Science publishes citation counts and for which we were able to find prices. This edition includes data for 8,422 journals as compared to 7005 journals in the previous edition. We were able to list more journals because the 2009 version of the Web of Science added approximately 1500 journals from which it previously did not collect citation information. Citation and article counts are underestimated for journals that have recently changed their ISSN numbers or have recently been added to the Web of Science listings.
Explanation of Data Fields
Title: The journal title is retrieved from the publisher's price list and from the JCR database.
ISSN: The International Standard Serial Number is retrieved from the JCR database. For journals that have a print edition, we use the print ISSN. For journals that do not have a print ISSN, but do have an electronic ISSN, we use the electronic ISSN.
Publisher: The journal publisher is retrieved from the JCR database and checked against publisher-supplied listings and web sites.
Subject: The subject of the journal is one or more of the following list: Agriculture, Biology, Chemistry, Computer Science, Economics, Education, Engineering, Geology, History, Humanities, Law, Mathematics, Medicine, Physics, Psychology, Social Science, and Miscellaneous (Nocat). Our categorization is coarser than the categorization provided by the JCR. Some journals labeled Nocat in the JCR database were re-categorized by hand when it was clear where they belonged.
Year First Published: This is the year in which the journal was first published. It is retrieved from a variety of sources.
Price Per Article: The total number of articles published by each journal in the five years 2004-2008 (the most recent years with data available) is retrieved from the JCR database. The price per article is simply the price of this journal for a year's subscription to an academic library (see below under "Calculation of Price" for details) divided by the average number of articles published per year.
Price Per Citation: From the JCR database, we obtain a "recent citation rate", for each journal in 2009. This is the number of times that volumes of a journal published in the years 2004-2008 were cited in 2009 by ISI-listed journals, divided by 5. The price per citation is the price of this journal for a year's subscription to an academic library (see below under "Calculation of Price" for details) divided by the recent citation rate.
Composite Price Index: The Composite Price Index (CPI) is the geometric mean of the Price Per Article and the Price Per Citation.
Profit Status: The profit status of the owner of a journal. In many cases, a journal owned by a non-profit organization will contract with a for-profit publisher to handle publication and fulfillment while the society generally retains control of pricing. The major commercial publishers have consistently declined to provide us with information about which of the journals they publish are owned by the publishers and which are published for non-profit societies. We have learned the ownership status of a large number of journals published by major commercial publishers by means of direct inquiries to editors, examination of journal web pages, and examination of copyright ownership notices in the journals. We have no doubt failed to discover all cases of non-profit ownership of journals published by commercial publishers and would be grateful for information about those we have missed. In a few cases we have not been able to determine the profit status of small publishers. These we have labeled profit-status "unknown." In calculating averages, these journals have been included with the journals labeled as “for-profit.”
Relative Price Index: The relative price index (RPI) for a journal is its CPI divided by the average CPI of non-profit journals in its subject category. Journals that have multiple subject listings are factored into the average CPI for each field that they belong to. The RPI of such a journal is its CPI divided by the average of the average of CPIs for the subjects listed for it.
Value: The value category is a broad categorization of a journal as "high value" "low value" or intermediate. A journal with an RPI less than 1.25 is classified as "good value", more than 2.0 as "bad value" and everything else as "medium". (The cutoff for bad value was reduced from 2.5 to 2.0 in 2009.)
When possible, we have obtained subscription prices for the 2010 edition of the journals charged to academic libraries located in the United States. (Prices quoted only in foreign currencies are converted to United States Dollars using the Currency Converter at current exchange rates.) The prices of most journals were retrieved from publisher's price lists, journal web sites and direct correspondence with journal editors and publishers. We found some prices for which other methods failed, by referring to Ulrich’s Periodicals Directory. If we were unable to find the 2010 price, but had the prices for 2009 and 2011, we used the mean of these two prices. If we could not find the 2010 price, but had either the 2009 price or the 2011 price, we used that price. Whenever available, we used the price of an institutional “online only” subscription. If institutional online-only subscriptions were not available, but a “print-plus-online” edition was available, we used that. If institutional online subscriptions are not available in any form, we used the price of the print edition. For journals that are priced with a “tiered structure”, we used the price charged to large, single-campus universities with enrollment of 25,000 or larger.
The first edition of journalprices.com was posted in November 2005. It used prices for the year 2004 and article and citation information for the years 1998-2002. The second edition was posted in 2007 and used 2006 subscription prices and citations in 2005 to articles published in the years 2000-2004. The third edition was posted in December 2008 and used prices for 2008 and citations in 2007 to articles published in the years 2002-2006. The fourth edition was posted in September 2009 and used 2009 subscription prices and citations in 2008 to articles published in the years 2003-2007. This edition was posted in March 2011 and uses prices for 2010 and citations in 2009 to articles published in 2004-2008.
For the first edition, we used an alternative ISI-published database, "Journal Performance Indicators" rather than "Journal Citations Reports" which we have used in later editions. The JPI, which we used in the first edition, reports recent citations in a different way from the JCR. The "recent citations" data from the JPI data includes all citations regardless of the year in which the citation occurred to articles written in the interval 1998-2002. "Recent citations" as reported by the JCR include only those citations to articles published in the most recent 5 years and cited in the current year. The JCR-based count of recent citations is therefore considerably smaller than the count of recent citations calculated by the JPI method. Consequently, our costs per citation are systematically higher in later editions than in the first edition.
Unfortunately, while there is a JCR for Science and for Social Science, there is not one for the Humanities. Thus we are forced to exclude some humanities journals that were included in our JPI based report.
In recent years, there have been many mergers and acquisitions by large commercial publishers. In previous editions, we followed the practice of the ISI in listing publications of publishers that were purchased by larger publishers under the name of their old publishers. In this edition, we list such journals as owned and published by the large publisher that purchased them.
We will update this database from time to time, making revisions and corrections that are pointed out to us. Please contact the website owner with any questions or proposed corrections.