In 1998, Congress extended copyright terms on both new and existing works. Lawrence Lessig tried unsuccessfully to have this extension overturned by the Supreme Court.
In this interview, Lessig explains the weakness of the economic argument for the copyright extension. First, even for new works, a longer copyright term confers very little incentive at the margin for creators. Moreover,
With respect to existing works, by definition it's not creating any incentives to produce because you're just granting a windfall to works that have already been produced. No matter what we do, Gershwin will not produce anything else. That extension is nothing more than what economists would call "rent-seeking," using property as a cover.
For Discussion. Do you think that those who were pushing for copyright extension would have accepted the economic logic which says that extending copyright terms for existing works has no marginal incentive effects, so that the extension should only apply to new works?