Since its origin, one of the key concerns regarding copyright law was the duration of its protection. Over the last half-century, there has been a strong advocacy to prolong copyright duration. In this respect, it is important to rigorously examine if a longer copyright duration is helpful in guaranteeing the earnings of authors from their works as well as the promotion of cultural creativity and diversity. This paper addresses these issues by adopting a business and economic analysis. Unlike what is generally accepted, this paper shows that a longer duration does not improve the author’s earnings, and that, furthermore, it impedes cultural creativity and diversity. The main reason lies in two factors often neglected, the weak bargaining power of the author and the principal agent-dilemma through private contracts under longer duration which result the structural under-performance of the publishers. As a solution, this paper proposes to shorten the copyright duration and shows that this is likely to increase the earnings of authors from their works and to enhance cultural diversity and creativity.