FILE - Federal Reserve Chair Janet Yellen speaks during a news conference December 13, 2017 in Washington, DC. (Alex Wong/Getty Images)WASHINGTON - President-elect Joe Biden has chosen former Federal Reserve Chair Janet Yellen to serve as treasury secretary, a pivotal role in which she would help shape and direct his economic policies, according to a person familiar with the transition plans.Yellen, who is widely admired in the financial world, would be the first woman to lead the Treasury Department in a line stretching back to Alexander Hamilton in 1789.Her nomination was confirmed to The Associated Press by a person who spoke on condition of anonymity to discuss Biden's plans.President-elect Joe Biden spoke Nov.