Shortening copyright that much might not change the median net present value of a creative work that much, but if there are enough heavy long-term sellers in th

Shortening copyright that much might not change the median net present value of a creative work that much, but if there are enough heavy long-term sellers in the top few percent, it might still noticeably impact the average NPV. Though I'm curious how those numbers might actually look like, myself. It might also have some unforeseen consequences on preservation, especially when the version of the work that gets released to the general public is of inferior quality to the master copy the remains hidden in the vaults (either due to limitations of the technology of the day, or because so far it wasn't supposed to have been released and all the public gets are some bootlegs of varying quality or even nothing at all)? Without copyright, one likely major incentive for the continued preservation of those master copies disappears, especially if that master copy is held by some commercial enterprise which must make money in order to survive. (With books that's less of an issue because it's easy to perfectly recover the original text even from a book with mediocre printing quality – with music and video on the other hand you're stuck with the limitations of the original publishing medium forever unless you can go back to the master copy.) So on the one hand, yes, I do agree that life + 70 years is somewhat on the too long side, and all the more so for out-of-print, orphaned or otherwise once-published-but-now-unavailable works. On the other hand I've also been enjoying quite a few CD/digital re-releases of vinyl-era music as well as some releases of tracks that had remained officially unreleased for a few decades, both of which likely wouldn't have happened if those works weren't still in copyright (and therefore of commercial value) at that point.