Resumen:
Media concentration has always been a controversial topic. In any media market, the dominant position of some companies may distort the free flow of information and, as a result, can decrease media pluralism and the quality of democracy. This article analyses 10 media and telecommunications product markets in Spain from 1984 to 2012. With this comprehensive and long-term approach, it concludes that content industries are moderately but increasingly concentrated, while technology industries are highly but decreasingly concentrated.