Yes, correct. We cleaned up the repo and removed outdated files that are not needed to replicate the figures and tables to avoid confusion. The dataset can also be found here: https://zenodo.org/record/4014076#.X1lgTbexVkw
We found that in some cases, some of the published articles are archived through the Internet Archive! (Yay!) Unfortunately, this doesn't amount to complete issues/volumes and seems to be by chance.
Yes. We checked that all journals were full OA journals (so nothing like the scenario you just described here). So the timeline looked like this: OA journal was actively publishing > then became inactive, but the content on the journal website was still accessible > and eventually the website and the content disappeared/became inaccessible.
In some cases, we found websites (other than the original journal website) that now host some individual issues, but not all of the content.
Exactly. We don't see OA as the problem. OA solves many issues that exist with traditional publishing and also makes it easier to preserve content in the first place. The problem lies with decreasing library budgets, rising subscription prices, and that preservation services often are not suitable for smaller OA journals.
LOCKSS provides a free option for publishers to join, but only accepts a limited number of OA publishers (https://www.lockss.org/use-lockss/publishers). A couple years ago the PKP launched their preservation service, which we're really excited about as it also offers free preservation (for OJS journals) and would help esp. those smaller journals that otherwise couldn't afford to enroll into preservation schemes.
