Janet Yellen, nominated by President Barack Obama to succeed Ben S. Bernanke as chairman of the Federal Reserve, is poised to become the most economically powerful woman in the world. Yellen, 67, would be the first female head of the 100-year-old Fed and also the first woman to lead any central bank among the Group of Seven economies, which include the U.K., Germany and Japan. Her appointment, if confirmed by the Senate, would put a woman at the pinnacle of the economics field, helping change a history of male-dominated culture among policy makers across the globe. “Given the shortage of women in important positions ... (full story)