Economic literature has above all sought to analyze the efficiency of the copyright system, either from a theoretical viewpoint on the basis of the theory of welfare, or from a more empirical viewpoint, analyzing how the system for managing copyright issues actually operates. But it has paid scant heed to the importance of the definition of the author and the work within these systems. Our contribution sheds light on the economic stakes of these definitions in terms of the efficacy of systems of copyright. Both artistic and technological developments have contributed to making artistic creation an increasingly collective practice, leading to a multiplicity of authors. Strategies deployed by the various actors to be recognized as authors hav...