Nature on The crisis in preservation cites the work
@eve.gd did at Crossref Labs.
www.nature.com/articles/d41...
Great timing considering that Crossref apparently just shut down Crossref Labs- the group that did this study and was working on a project to address it. Funny they don't mention that.

Act now to stop millions of research papers from disappearing
Digital preservation is not keeping up with the growth of scholarly knowledge. Recognizing its causes is the first step to securing records everywhere for future generations.