The Economics of Journal Publishing


Case study: Ecology

Prices and publishers

Who publishes the top tier?

Cumulative plots

Estimating circulation

Journal numbers over time

Comparing other fields

Prices and publishers across disciplines

Cumulative plots across disciplines

Top science journals


Economics of ecology journals

Will open access be able to compete?

Costs and benefits of site licenses

Electronic subscriptions: A boon for whom?

Value and price by journal

Contact Information

Carl T. Bergstrom

Department of Biology
University of Washington
Box 351800
Seattle, WA 98195-1800

Ecology journals: Visualising the market with cumulative plots

Cumulative plots provide a useful view of the relation between price and pages or price and citations.

Imagine a hypothetical librarian who was concerned only with acquiring as many ecology journal pages as possible for a given amount of money. He could do so by purchasing journal subscriptions in order of increasing price per page until his budget was exhausted. The cumulative curve below shows the number of pages acquired by this librarian, given the size of his budget.

Cumulative plot for pages
[ View a high-detail PDF version of this image ]

For example, the plot shows that he could acquire half of the pages published in ecology in the year 2000 for about $12000 - roughly a fourth of the cost necessary to acquire all journals in the field.

Publisher types are indiciated by the color of shading under the cumulative curve. Non-profit journals, in turquoise, are concentrated in the early part of the curve. This means that the librarian would first purchase a number of non-profit journals, for these offer the best "value" in terms of price per page. Note also that the slope of the cumulative curve at any given point indicates the cost-per-page for the corresponding journal.

The rectangular bars below and to the left of the cumulative curve indicate the fractional breakdown of price (horizontal bar) and pages (vertical bar) at each given point along the price and page scales. For example, at the $1,000 point, the price bar is almost entirely turquoise, indicating that the bulk of spending to this point will have been for non-profit journals. At the $55,000 point, where all journals have now been purchased, the bar is about 10% turquiose, 45% grey, and 45% cream, indicating that the majority of those $55,000 have gone to for-profit and jointly-purchased journals. The vertical bar can be interpretted similarly, with respect to pages rather than dollars.

Suppose instead of trying to maximize the number of pages purchased for a given price, the hypothetical librarian tried instead to maximize the number of citations TO journals in his library. In this case, he would buy journals in order of increasing citations per page. His purchasing, in this case, would be reflected by the cumulative plot for total citations, shown below.

Cumulative plot for citations
[ View a high-detail PDF version of this image ]

Again, most of the journals in the initial (leftmost) part of the curve are turquoise non-profits. Thus the citation-maximizing librarian, like the page-maximizing librarian, will first purchase a number of non-profit journals; these offer the best "value" in terms of cost per citation. In this case, the slope of the cumulative curve changes even more abruptly than in the cumulative curve for pages. For under $5,000, the librarian can acquire journals representing half of the citations in the literature!

In practice, librarians will not actually use purchasing rules as simple as "maximizing pages" or "maximizing citations" caricatures presented on the previous page. Instead, they we expect that they will be sensitive to much more subtle distinctions of quality and value.

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Last modified September 4, 2002
Copyright © 2002 Carl T. Bergstrom