OA continues to grow. But when will it be…done? When will everything be published as Open Access?

Using data from our recently-published PeerJ OA study, we took a crack at answering that question. This data we’re using comes from the Unpaywall database–now the largest open database of OA articles ever created, with comprehensive data on over 90 million articles. Check out the paper for more lots more details on how we assembled the data, along with assessments of accuracy and other goodies. But without further ado, here’s our projection of OA growth:

In the study, we found that OA is increasingly likely for newer articles since around 1990. That’s the solid line part of the graph, and is based on hard data.

But since the curve is so regular, it was tempting to extend it so see what would happen at the current rate of increase. That’s the dotted line in the figure above. Of course it’s a pretty facile projection, in that no effort has been made to model the underlying processes. #limitations #futurework 😀. Moreover, the 2040 number is clearly too conservative since it doesn’t account for discontinuities–like the surge in OA we’ll see in 2020 when new European mandates take effect.

But while the dates can’t be known for certain, what the data makes very clear is that we are headed for an era of universal OA. It’s not a question of if, but when. And that’s great news.