Washington, Aug. 6: Christina Romer, one of US President Barack Obama’s most pivotal economic advisers, is resigning, a change that comes as the White House struggles to show signs of clear economic gains to a hurting nation. Ms Romer, the head of the Council of Economic Advisers, announced her resignation on Thursday, effective from September 3. She becomes the second high-level Obama aid to leave this summer, following the resignation of White House budget director Peter Orszag. She will return to her job as a professor of economics at the University of California. The White House cast the decision as an unsurprising one driven by family reasons.