Gabre-Madhin left her earlier job, as a World Bank senior economist in Washington, DC, in part because she was disturbed by the 2002 famine in Ethiopia -- after a bumper crop of maize the year before. With prices depressed, many farmers simply left their grain in the field in 2001. But when the rains failed in 2002, a famine of 1984 proportions threatened the country. Her dream: to build a market that protects the African farmer, who is too often living at the mercy of forces beyond his or her control.

The director of the International Food Policy Research Institute, Madhin studies market reforms, market institutions, and structural transformation in Africa, and works to create "a world free of hunger and malnutrition."

Ngozi Okonjo-Iweala, the former Finance Minister of Nigeria

Journalist Andrew Mwenda

Andrew Mwenda is a print, radio and television journalist, and an active critic of many forms of Western aid to Africa. Too much of the aid from rich nations, he says, goes to the worst African countries to fuel war and government abuse. Such money not only never gets to its intended recipients, Africa's truly needy -- it actually plays a part in making their lives worse.

Mwenda has been working as a journalist with the Daily Monitor newspaper in Kampala since the mid-1990s, and hosted a radio show, Andrew Mwenda Live, since 2001; in 2005, he was charged with sedition by the Ugandan government for criticizing the president of Uganda on his radio show, in the wake of the helicopter crash that killed the vice president of Sudan. He has produced documentaries and commentary for the BBC on the dangers of aid and debt relief to Africa, and consulted for the World Bank and Transparency international. Right now, he's a John Knight Fellow at Stanford University.