From CUP:
Cambridge University Press is launching a new policy to prevent charging both authors and subscribers for Open Access journal content (so-called double-dipping).
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The new policy discounts 2016 subscription prices for journals that have received Open Access (OA) Article Processing Charges (APCs) from authors in the last full journal volume (that is, in 2014). If the fraction of OA articles in a journal was at least 5 per cent and the income from APCs was at least £5,000 [approx. $12,000/USD] , then the Press is discounting renewed subscriptions by the lower of the percentage OA or the percentage APC income. All Open Access articles are included, except those in supplements published in addition to a volume’s subscription content. Subscribers already receiving a substantial discount on a journal’s subscription price, via a consortium package for example, will not receive an additional discount on their collection access fee as a result of these changes.
Read the Complete Announcement
See Also: Cambridge U. Press Open Access FAQ