American economist and educator who served as the chief economist of the World Bank (1991–93), secretary of the U.S. Treasury (1999–2001), and president of Harvard University (2001–06). From 2009 he was director of the National Economic Council in the administration of Pres. Barack Obama (Obama, Barack).

Summers was the son of economics professors. After earning a doctorate in economics at Harvard in 1982, he served on the President's Council of Economic Advisers before returning to Harvard in 1983; at age 28 he became one of the youngest individuals in the school's history to be awarded a tenured faculty position. In 1987 he became the first social scientist to receive the Alan T. Waterman Award of the National Science Foundation. In 1993 he received the John Bates Clark Medal, bestowed biennially on an outstanding American economist under age 40.

Summers returned to Washington, D.C., in 1991 as chief economist at the World Bank. In December of that year, Summers wrote a private memo that characterized developing countries as “under-polluted” and suggested that toxic waste should be sent to such areas as an exercise in economic efficiency. When the contents of that memo were leaked to the press, there were calls for his resignation. Summers, however, remained at the World Bank until 1993, when he was appointed undersecretary of the Treasury for international affairs. In that role, he crafted the U.S. response to the collapse of the Mexican peso in 1995 and contributed to the international economic recovery efforts in the wake of the 1997–98 Asian financial crisis. He moved to the top spot in the Treasury Department in 1999 and served as the principal economic adviser to Pres. Bill Clinton (Clinton, Bill).

In 2001 Summers was appointed Harvard's 27th president. He soon drew criticism for his abrasive personal style when he privately admonished Cornel West (West, Cornel)—an authority on African American studies and religion who held one of Harvard's most prestigious professorships—for missing too many classes, inflating grades, and spending too much time in political and self-promotional activities. In response, West publicly accused Summers of disrespect, identified himself as a scholar-activist, and left Harvard for a professorship at Princeton University. Summers also attracted controversy for his proposed reforms at Harvard. Important elements of his agenda consisted of removing key decision-making power from the university's separate schools and locating it in the president's office, tightening grading standards, pressing senior professors to teach undergraduates, and focusing greater attention on societal concerns. Summers also sought to alter the curriculum to emphasize students' acquiring deep knowledge rather than chiefly surveying “ways of knowing” in various disciplines. In 2005 Summers suggested that innate differences between the sexes might explain why fewer women than men pursue careers in science and engineering. Although he later apologized for his remarks, the resulting furor led to his resignation in 2006.

Later that year Summers became Charles W. Eliot University Professor at Harvard and began writing a column for the Financial Times. In 2008 Obama named him director of the National Economic Council, and Summers assumed the post following Obama's inauguration in 2009.