[icebraining]

That's true, though it should be possible to study the effects of the Act of 1976, which extended copyright duration in the US from a maximum of 56 years to life of author + 50 years.

And it seems this was done:

"Despite the logic of the theory that increasing copyright protection will increase the number of copyrighted works, the data do not support it. Instead, our findings demonstrate that the historic long-run growth in new copyrighted works is largely a function of population"

http://vanderbiltlawreview.org/articles/2009/11/Ku-et-al.-Do...

[sirmarksalot]

That also doesn't seem surprising in the least, though some properly incentivized individuals might feign surprise. Using the same gut logic, very few people are thinking 100 years in the future when they decide to take on a project. 56 years seems long enough that a creator would be able to work without worrying about getting ripped off.

An argument could be made that traders at large holding firms would value IP more highly with a longer term, thus allocating more money, and incentivizing production, but there are so many links involved that I seriously doubt much of that could hope to make it back to the artist.

Anyway, I was just responding to the implication that a lack of objective data is enough to seriously consider abolishing copyright altogether.