> So there is a cutoff before 1964. However, it's not at all clear to me how many times the copyright holders didn't renew their copyrights. I would be unsurprised if the big publishers did typically renew them.
That doesn't sound that surprising to me either, but I don't think that matters for the claim that most are PD now. My intuition would be that big publishers wouldn't be responsible for a large percentage of the published titles in that time period. Certainly, from the standpoint of units sold they would be, but not distinct works.
There's a lot more niche, technical, academic, low-end, etc works even though most people consume the mass-market popular stuff. I would expect that all those long-tail things to be the ones that never got renewed, and to be in the majority as far as titles go.
That doesn't sound that surprising to me either, but I don't think that matters for the claim that most are PD now. My intuition would be that big publishers wouldn't be responsible for a large percentage of the published titles in that time period. Certainly, from the standpoint of units sold they would be, but not distinct works.
There's a lot more niche, technical, academic, low-end, etc works even though most people consume the mass-market popular stuff. I would expect that all those long-tail things to be the ones that never got renewed, and to be in the majority as far as titles go.