Washington — Secretary of State Hillary Rodham Clinton told an international conference that educating women and girls helps them substantially contribute to their communities.

"The evidence shows conclusively that even one extra year of schooling leads to significantly higher wages for women and girls, which allows them to lift up themselves, their families, and contribute to their communities and countries," Clinton said May 26 at the Paris launch of the UNESCO Global Partnership for Girls' and Women's Education.

"We have seen that when women and girls have the opportunity to pursue education, GDP [gross domestic product] grows for entire societies," she said.

Clinton is the first secretary of state to visit the UNESCO headquarters in Paris.

The secretary said the reason for educating women and girls is not only economic.

"Birth rates, HIV infections, incidents of domestic violence, female cutting all decline when education rises," Clinton told the conference. "Fully one-half of the drop in child mortality achieved between 1970 and 1990 can be attributed to increased education for women and girls."

At the conference, U.N. Secretary-General Ban Ki-moon said the opportunity to acquire knowledge creates a new generation of mothers who raise educated and empowered young women.

"Education sends a message -- a message of confidence and hope," Ban said. "It tells that child, 'You have a future, what you think matters.'"

According to UNESCO, there are an estimated 39 million girls of lower secondary school age across the world not enrolled in either primary or secondary school. Two-thirds of the world's 796 million illiterate adults are women, and only about a third of countries have achieved gender parity in secondary school enrolment, UNESCO says.

Clinton said that in the poorest communities, girls who are out of school today are more likely than boys never to start school. This contributes to economic and social stagnation for those communities, she added.

"No society can achieve its full potential when half the population is denied the opportunity to achieve theirs," Clinton said.

The United States has joined UNESCO in a new study that aims to examine education for women and girls around the world. Clinton said this study will focus on two critical areas: adult literacy and secondary education, which experts believe is the critical juncture in women's and girls' education.