A while back, there was some buzz about a paper showing that, for a particular subset of journals, there was essentially no correlation between Impact Factor and journal subscription price. I think, though my google-fu has failed me, that the paper was Is this journal worth $US 1118? (pdf!) by Nick Blomley, and the journals in question were geography titles. Blomley found "no direct or straightforward relationship" between price and either Impact Factor or citation counts. He also looked at Relative Price Index, a finer-grained measure of journal value developed by McAfee and Bergstrom. He didn't plot that one out, so I will:

There is some circularity here, since RPI is calculated using price, but once again I'd call that no direct or straightforward relationship.

All this got me wondering about the same analyses applied to other fields and larger sets of journals. My first stop was Elsevier's 2009 price list, handily downloadable as an Excel spreadsheet. It doesn't include Impact Factors, but the linked "about" page for each journal displays the IF, if it has one, quite prominently. So I went through the Life Sciences journals by hand, copying in the IFs. I ended up with 141 titles with, and 90 titles without, Impact Factors. As with Blomley's set, there was no apparent correlation between IF and price:

Interesting, no? If the primary measure of a journal's value is its impact -- pretty layouts and a good Employment section and so on being presumably secondary -- and if the Impact Factor is a measure of impact, and if publishers are making a good faith effort to offer value for money -- then why is there no apparent relationship between IF and journal prices? After all, publishers tout the Impact Factors of their offerings whenever they're asked to justify their prices or the latest round of increases in same.

There's even some evidence from the same dataset that Impact Factors do influence journal pricing, at least in a "we can charge more if we have one" kinda way. Comparing the prices of journals with or without IFs indicates that, within this Elsevier/Life Sciences set, journals with IFs are higher priced and less variable in price:

About the time I was finishing this up, I came across a much larger dataset from U California's Office of Scholarly Communication. I've converted their html tables into a delimited text file, available here: UCOSC.txt. For my next trick I'll see what information I can squeeze out of a real dataset (there are about 3,000 titles in there).

Oh, and if anyone wants it, the Elsevier Life Sciences data are in this Excel file: ElsevierLifeSciPriceList.xls.