Yet the other two principals in Mr. Obama’s economic inner circle  Ms. Romer and Peter R. Orszag, his budget director  left in recent weeks, largely for personal reasons, giving Mr. Obama the opening to remake his team. But for both vacancies, Mr. Obama has now picked people from within his administration.

Image Austan D. Goolsbee will succeed Christina D. Romer as chairman of the Council of Economic Advisers. Credit... ABC This Week, Fred Watkins, via Associated Press

To succeed Mr. Orszag, who left in July, the president nominated Jack Lew, who has been a deputy secretary of state and was a budget director in the Clinton administration. Mr. Lew is not on the job yet but is awaiting confirmation by the Senate.

Because Mr. Goolsbee has been confirmed by the Senate as a member of the Council of Economic Advisers, he does not need approval to become the chairman  not a small consideration at the White House, given how often the president’s nominees become bogged down in partisans skirmishes.

Another factor initially worked against Mr. Goolsbee’s elevation  his sex  and that also played a part in his being passed over for the chairman post at the start of the administration. Ms. Romer was the only woman among Mr. Obama’s top economic advisers, and administration officials considered whether to name a woman to replace her.

Also, at 41, Mr. Goolsbee would be the youngest chairman since Arthur M. Okun held the job from 1968 to 1969 under President Lyndon B. Johnson. (Mr. Okun is known for Okun’s Law, which describes the relationship between changes in employment and changes in output.)

But Mr. Goolsbee, an amateur comic as well as an economist, was a favorite within the White House, where many colleagues felt he had earned the chairmanship. He has tense relations with Mr. Summers, however, after policy disputes in the early crisis-driven debates over the rescues of the financial industry and Chrysler, among other issues.

Mr. Goolsbee, who has a free-market bent, opposed bailing out Chrysler. He did not prevail, but Mr. Obama personally sought his arguments.