External recruiting at least weakly improves the quality of the pool of applicants, but the incentive implications are less clear. Using a contest model, this paper investigates the pure incentive e¤ects of external recruiting. Our results show that if workers are heterogeneous, the opening of a …rm's career system may lead to a homogenization of the pool of contestants and, thus, encourage the …rm's high ability workers to exert more e¤ort. If this positive e¤ect outweighs the discouragement of low ability workers, the …rm will bene…t from external recruiting. If, however, the discouragement e¤ect dominates the homogenization e¤ect, the …rm should disregard external recruiting. In addition, product market competition makes opening of the career system less attractive for a …rm since it increases the incentives of its competitors'workers and hence strengthens the competitors.