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 JCR database records the total number of articles published by each journal in the five years 2007-2011 (the most recent years with data available) . 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 2004-2009 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 calculated by dividing its CPI  by the median  CPI of  those non-profit journals in its subject category that  have positive subscription prices.  Journals that have multiple subject listings are factored into the average CPI for each field that they belong to.   In previous editions, we calculated a journal's RPI by dividing its  CPI by the median CPI of all non-profit journals in its subject category including those that were freely available
online at zero subscription cost.    With rapid growth in the number of ``open access'' journals,  many of which are supported either by author fees or by government subsidies, we decided that a more appropriate yardstick for costs would be
the average subscription prices of non-profit journals that charge for subscriptions. 

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 1.15 is classified as "good value", more than 1.75 as "bad value" and everything else as "medium".  Because
the current edition does not include zero-cost journals in its calculation of the average costs per citation or per article of non-profit journals,  the calculated RPI's for all journals fell substantially.   To compensate for this change, we reduced the
cutoff  between "high value"  and "medium value" from an RPI of 1.25 in the previous edition  to  an RPI of 1.15  in this edition and the cutoff between "medium value" and "low value" from 2.0 in the previous edition to 1.75 in this edition. 

Sources of Price Information

When possible, we have obtained subscription prices for the 2013 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 could not find the 2013 price, but had either the 2012 price or the 2014 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.

Historical Information

The current edition is the sixth edition of journalprices.com 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. The fifth  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 the fifth and sixth editions,  we try to 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.