Media concentration has been an issue around the world. To some observers the power of large corporations has never been higher. To others, the Internet has brought openness and diversity. What perspective is correct? The answer has significant implications for politics, business, culture, regulation, and innovation. It addresses a highly contentious subject of public debate in many countries around the world. In this discussion, one side fears the emergence of media empires that can sway public opinion and endanger democracy. The other side believes the Internet has opened media to unprecedented diversity and worries about excessive regulation by government. Strong opinions and policy advocates abound on each side, yet a lack of quantitative research across time, media industries, and countries undermines these positions. This book moves beyond the rhetoric of free media and free markets to provide a dispassionate and data-driven analysis of global media ownership trends and their drivers. The book covers thirteen media industries, including television, newspapers, book publishing, film, search engines, ISPs, wireless telecommunication, and others across a 10- to 25-year period in thirty countries. After examining these countries, this book offers comparisons and analysis across industries, regions, companies, and development levels. It calculates overall national concentration trends beyond specific media industries, the market share of individual companies in the overall national media sector, and the size and trends of transnational companies in overall global media.