Subscribe-to-Open (S2O) was developed by Annual Reviews and Berghahn Books and has been adopted by EDP Sciences, IWA Publishing and others. Each year, the publisher sets a renewal threshold; if reached, the entire content of that volume is published open access. If the threshold is missed, the volume reverts to closed access. The model avoids author-side APCs and the equity issues they raise, preserves the workflow of subscription procurement and is approved as a route to Plan S compliance. It depends on a free-rider problem being mitigated by community norms and short subscription suspension windows.
References
- Annual Reviews S2O documentation. Crow R, Gallagher J, Naim K 'Subscribe to Open: A practical approach to flipping subscription journals' Learned Publishing 2020.