New York City in the world at 103, including former Mayor Michael Bloomberg. New York also had the highest density of millionaires per capita among major U.S. cities in 2014, at 4.6% of residents. New York City is one of the relatively few American cities levying an income tax (currently about 3%) on its residents. New York is a global hub of business and commerce. The city is a major center for banking and finance, retailing, world trade, transportation, tourism, real estate, new media, traditional media, advertising, legal services, accountancy, insurance, theater, fashion, and the arts in the United States; while Silicon Alley,
Silicon polymers, elastomers, and resins. In the late 20th century, the complexity of the crystal chemistry of silicides was mapped, along with the solid-state chemistry of doped semiconductors. Because silicon is an important element in high-technology semiconductor devices, many places in the world bear its name. For example, Santa Clara Valley in California acquired the nickname Silicon Valley, as the element is the base material in the semiconductor industry there. Since then, many other places have been dubbed similarly, including Silicon Forest in Oregon, Silicon Hills in Austin, Texas, Silicon Slopes in Salt Lake City, Utah, Silicon Saxony in Germany, Silicon