My argument against copyright protection for folklore is that the folklore has already been produced, and therefore giving it protection would create no added incentive to produce creative works. Here’s Tyler’s response:
Folklore has already been produced. TC: Of course you could say the same for a good deal of music. Why treat folklore differently?The difference is that the music in question was produced while copyright laws were in effect. The expected monopoly rents resulting from copyright may therefore have been part of the motivation for producing the music. Of course, revoking a given work's copyright would not cause it to blink out of existence. But a precedent for revoking copyrights would indicate to potential future creators that the expected rents won't be there, thereby reducing their incentive to create. The same cannot be said of folklore, because there was no copyright to begin with; thus, there is nothing to revoke.
This is very much the same issue raised by the "Mickey Mouse Extension" Acts. Disney lobbies for retroactive extension of the copyright period whenever Mickey Mouse's copyright is about to expire. But a retroactive extension does nothing (or almost nothing) to encourage more creative work; it only extends the monopoly. The granting of copyrights to existing folklore is just a radical form of retroactive extension, which creates monopoly rents without the corresponding gain from the encouragement of new work.