Private Copying, Appropriability, and Optimal Copying Royalties

THERE is little doubt that the small-scale, decentralized reproduction of intellectual property-private copying-is a widespread practice, but its precise extent and economic effects are the subject of considerable dispute. Although the owners of copyrighted computer programs, printed matter, and audio and video tapes have claimed extensive harm from copying,1 and have occasionally succeeded in having legislation introduced that would compensate them for this harm,2 the effect of copying is not well understood and its quantitative effect is poorly measured.