Mark Zuckerberg, the most generous philanthropist in the U.S. in 2013

Entrepreneur Mark Zuckerberg and his wife, Priscilla Chan, were among the most generous philanthropists in the United States in 2013, and they donated 18 million Facebook shares, valued at more than $ 970 million to a nonprofit association of Silicon Valley in December. The publication Chronicle of Philanthropy reported Monday that Zuckerberg donation was the largest charitable donation recorded in 2013 and placed the young couple on top of the annual list of the most generous couples posing magazine. The contributions made ​​by major donors 50 last year totaled 7.700 million , plus commitments for 2,900 million. The editor of the Chronicle said the most significant event of the list was the amount donatedby living philanthropists who joined the same amount achieved in the previous two years combined. "This clearly shows that the economy is improving and people are much less cautious," said Stacy Palmer , editor of the Chronicle. Some of the major donors in the United States do not appear in the list of 2013, not because left to be generous, but because 2013 contributions were accounted as promises of previous years. For example, the Microsoft co-founder Bill Gates and his wife Melinda gave its founding just over 181.3 million last year , but was covering a promise to donate 3,300 million made ​​in 2004. The co-founder of the CNN Ted Turner and director of Berkshire Hathaway Warren Buffettalso made ​​large deliveries in response to previous promises. To get on the list it was necessary to make donations by at least 37.5 million . Of the 50 included in this, they made ​​42 contributions of 50 million or more. Ten of the 50 grants listed were made ​​by heirs , including that of the second donor in 2013, George Mitchell, an entrepreneur from Galveston, Texas, who amassed his fortune by investing in energy and real estate. In the No. 3 left Nike director Philip Knight and his wife Penelope , Portland, Oregon, who donated 500 million for cancer research at the Oregon Foundation for Science and Health. The fourth greatest philanthropist was former New York Mayor Michael Bloomberg , who made ​​deliveries 452 million for activities artistic, educational, environmental protection, public health and other causes. Nineteen people or couples on the list have signed the Pledge Donate launched by Bill Gates and Warren Buffett in 2010 . More than 120 people or more wealthy families in the world have pledged to donate at least half their wealth to charity since the movement began.