The new World Bank chief should have a keen understanding of major global development challenges and facilitate solutions to those critical problems, a U.S. expert said on Friday as the Washington-based international financial agency is seeking a successor to its outgoing President Robert Zoellick."The World Bank is potentially far more decisive than a bank. At its best, the Bank serves as a powerhouse of ideas and a meeting ground for key actors who together can solve daunting problems of poverty, hunger, disease and environmental degradation, "observed Jeffrey Sachs, director of the Earth Institute at Columbia University.However, without incisive leadership, the World Bank has often seemed like just a bank, the economist said in an article titled " How I would lead the World Bank,” which appeared on The Washington Post on Friday. He added that "unfortunately, Washington has backed at the helm bankers and politicians who lack the expertise to fulfill the institution’s unique mandate.”