> Even though I walk through the valley of the shadow of death, I fear no evil. (Psalm 23:4)
Some are calling it “the copyright hole”, but I think the copyright valley describes the graph’s appearance, especially when you mash it up with Psalm 23 (above):
_The Atlantic_ has [the report], with a link to [the study].
[the report]: http://www.theatlantic.com/technology/archive/2013/07/the-hole-in-our-collective-memory-how-copyright-made-mid-century-books-vanish/278209/
[the study]: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2290181