Originally copyright was for 14 years from publication, with an optional 14 year renewal. So variable terms aren't unheard-of — you just ask the copyright offic

Originally copyright was for 14 years from publication, with an optional 14 year renewal. So variable terms aren't unheard-of — you just ask the copyright office if it's been renewed. Coincidentally (or not) this term is very close to the estimated economically optimal copyright term.[1] [1] https://rufuspollock.com/papers/optimal_copyright_term.pdf https://rufuspollock.com/papers/optimal_copyright_term.pdf