Kent Anderson has published "Supply, Demand, and the Subscription Model in Scholarly Publishing—An Analysis" in The Scholarly Kitchen.
Here's an excerpt:
5. Denials (turn-aways) to archival content remain high. Perhaps the most interesting aspect of the dataset comes with the percentage of denials to the backfile, which represented 60% of all denials (turn-aways). Even looking at content 10 years old or older, denials represented 49% of the total, dropping to 37% for content 20 years old or older. Archives and backfiles are still sought after, as these data and the abstract usage combined to illustrate.