Economy of New York City feet (37.2 million m) that same year, is the largest central business district in the world. New York City is distinctive for its high concentrations of advanced service sector firms in the law, accountancy, banking and management consultancy fields. It is the top global center for the advertising industry, which is metonymously called "Madison Avenue". Silicon Alley, metonymous for New York's broad-spectrum high technology sphere, continues to expand. Finance, high technology, real estate, insurance, and health care all form the basis of New York's economy. The city is also the nation's most important center for mass media, journalism, and publishing.
Concentration of media ownership in Turkey Radio and Television Enterprises and their Media Services (2011), for audio-visual media. The Turkish Competition Authority ("") is entitled to take action against distortion of competition according to another law, i.e. the Law on the Protection of Competition. Therefore, as for the broadcasting sector there are sector-specific regulatory safeguards against a high horizontal concentration. For instance, the Law requires companies that are about to take over or merge with others to seek permission from the Radio and Television Supreme Council (Radyo ve Televizyon Üst Kurulu- RTÜK) and to inform it about transactions not later than 30 days after their completion.