Andreas Haupt examines why employees in different professions receive different wages and why wage inequality in Germany is increasing. He analyzes the impact of profession-specific market entry barriers, which can manifest in companies' recruitment schemes that heavily consider candidates with specific professional qualifications, such as engineers or banking specialists. These barriers are also found in legally mandated regulations, known as licenses, regarding the recruitment of doctors, judges, or speech therapists. The author demonstrates that the stronger the market entry barriers, the higher the wages of employees in that profession; the lower the wage inequality within the profession, and the smaller the wage differences, among other factors, between men and women within the profession.