Harvard University's next president, Lawrence Summers, is characterised by friends as driven and energetic. Even his tennis game, they say, is aggressive.
The nephew of two Nobel prize winners in economics - Paul Samuelson and Kenneth Arrow -he completed his doctorate in economics at Harvard at the age of . At 28, he became the youngest professor to be awarded tenure at Harvard. By 38, he had received the John Bates Clark medal for economics and, at 44, he was named United States treasury secretary.
"His many admirers within and beyond Harvard know him to be someone of exceptional energy and creativity, someone who inspires people to do their best work," said Robert Stone Jr, chairman of the university's selection committee.
In Dr Summers, now 46, Harvard gets a proven administrator, comfortable in the halls of wealth and political power, who is also an academic. The main criticism of him is that he acted arrogantly when he was younger. He says he has matured and will run the school "collegially".
In 1991, Dr Summers became chief economist at the World Bank, he was appointed undersecretary of the treasury for international affairs in the Clinton administration in 1993 and he became treasury secretary, in 1999.
Dr Summers was born in New Haven, Connecticut, and spent most of his childhood in Penn Valley, a suburb of Philadelphia. He was educated in the Lower Merion public schools.
He and his wife, Victoria, a tax attorney, have ten-year-old twin daughters, Pam and Ruth, and a seven-year-old son, Harry.
Dr Summers has not yet specified what he plans to do at Harvard, which will continue to be run by Neil Rudenstine until July.