Well-funded arguments are often made that copyright should last forever, replacing its original purpose (encouraging the creation of new works) with a plainly proprietary system of cultural ownership. Eric Crampton explains why this is a bad idea.
Even from the perspective of a profit-seeking artist, copyright is a double-edged sword. Stronger copyright both increases the rewards from having produced a piece of work and increases the cost of creating new works.
Too weak of copyright can mean that too few works are created, although artists have gotten far better at working out alternative ways of earning a living when, regardless of the letter of copyright law, enforcement has become difficult. Further, at standard time discounting rates, a 20-year extension to copyright’s term might provide only about a two percent increase in the value of any earned royalties. It is not particularly plausible that many new works would come into existence because of that slight increase.
On the other side, too strong of copyright can surely kill new creation. Artistic works feed off each other. New works build on older traditions, reinterpreting old folk tales and old folk tunes for new generations. The Brothers Grimm collected and published older folk tales like Cinderella and Sleeping Beauty in the 1800s. In the 1900s, Walt Disney brought those stories to life in a new form. In the 2000s, well, it is hard for new innovation to occur because copyright law, at least in the United States, has frozen the usage of most important works produced since 1923. An extension of copyright’s duration does far more to reward those who own the rights to existing works than it does to encourage new creation.