Former U.S. President Bill Clinton says economic troubles in the U.S. should not stop the global powerhouse from making investments in development in the rest of the world.

Speaking Tuesday at the start of his third annual meeting of the Clinton Global Initiative, the former president said most places are facing greater difficulties than the U.S.

The invitation-only event in New York brings together heads of state, business and religious leaders, media figures, and top philanthropists to discuss ways to bring about social change. Topics for this year's three-day meeting include creating jobs, sustainable consumption, and increasing the reach of programs that empower women.

New York Times columnist Nicholas Kristof spoke to the latter issue Tuesday, saying one important and inexpensive way to achieve greater development is putting more girls in school. He said that simple change can drive economic growth, improve health care and reduce conflict.

Along those lines, South African Archbishop Desmond Tutu and former Irish President Mary Robinson pledged to work toward ending child marriage, a practice they said affects as many as 10 million girls each year.

Ms. Robinson said that when girls marry young, they often leave school, and are at greater risk of dying during childbirth, and of having their children die young.

U.S. President Barack Obama is scheduled to speak Wednesday about how to build good environmental and social practices into the everyday business of running companies and governing.