After the studio system's collapse in the 1950s, actors and their agents fought for billing on a film-by-film basis. This, combined with changes in union contracts and copyright laws, led to more actors and crew members being included in the credits sequence, expanding its size significantly. As a result, since the late 1960s, a significant amount of the billing is reserved for the closing credits of the film, which generally includes a recap of the billing shown at the beginning. In addition, more stars began to demand top billing.