The basic problem of the primary literature is that the material to be published grows more rapidly than the number of people or institutions interested in buying and/or using it. A smaller, but still nagging, difficulty is that unit costs increase more rapidly than publishers are able to increase unit productivity.
... But in the last analysis, the primary literature would easily be able to continue basically unchanged, were it not for the fact that the demand has stabilized, while the supply of material has not yet done so.
-David E. Gushee J. Chem. Doc. 1970, 10, 30-32
Gushee goes on to discuss the decline of ACS journal subscription rates and the simultaneous increase in total pages printed and journals published. One wonders to what extent these trends continued over the last 36 years and how this phenomenon may driving the current escalation in journal costs.
About this "price squeeze" and a publisher's inability to escape it, Gushee writes:
A scientific society cannot, however, control cost as the typical business can. In journal publishing, the only real cost we can save is the page we don't print. And to restrict the number of pages printed is to interfere with the dissemination of knowledge, which is, after all, the basic reason the Society exists in the first place.
There are many interesting tidbits in this Back to the Future article, but perhaps none more so than the following:
Should the number of pages go over some critical number, then we get into a position of having to charge such a high price that individuals can no longer afford the journal. Chemical Abstracts, as an entity, reached that point some years ago and can no longer be considered a publication for individual subscriptions.
How expensive does a journal need to become before it can no longer be considered a publication for individual libraries? When that point is reached, who is responsible?