This article studies reasons for internal hiring, i.e., re-assigning or promoting an
employee instead of recruiting an external candidate. We exploit a representative
survey of establishments covering all European Union countries to measure employers’ search for internal candidates. Internal search is a widespread practice: 66% of establishments typically search internally. The accumulation of specific skills and the provision of incentives for employees are the main advantages of hiring internally in the theoretical literature. Ordered probit estimates show that on-the-job training and internal search are positively associated. On the contrary, incentive schemes such as variable pay are not associated with employer search. These results help to assess competing theories, and in particular, suggest that specific human capital is an important driver of internal hiring. Finally, we uncover two interesting facts that need further research: internal hiring is less likely in service firms and in noncompetitive product markets.