David Hamilton Koch (born May 3, 1940) is an American businessman, philanthropist, political activist, and chemical engineer. He is a co-owner (with older brother Charles) and an executive vice president of Koch Industries, a conglomerate that is the second-largest privately held company in the United States. Koch is a major patron of the arts and has contributed to several charities including Lincoln Center, Sloan Kettering, a fertility clinic at New York-Presbyterian Hospital and the American Museum of Natural History's David H. Koch Dinosaur Wing. The New York State Theater at Lincoln Center, home of the New York City Ballet was renamed the David H. Koch Theater in 2008 following a gift of 100 million dollars for the renovation of the theater. Condé Nast Portfolio described him as "one of the most generous but low-key philanthropists in America". Koch is the fourth richest person in America as of 2012, and the second-richest resident of New York City as of 2010.