WASHINGTON — America has never seen anything quite like this: The president and president-elect acting like co-presidents, consulting and cooperating on the day's biggest crises.

"It's pretty unusual," said George Edwards, a presidential expert at Texas A&M University, in College Station.

What Princeton University professor Julian Zelizer calls "the split-screen presidency" is the result of several historic forces converging this fall:

• The 24-7 nature of the global economy, which demands timely reaction.
• Incoming and outgoing presidents who have personal and political reasons to show that they can manage a crisis.
• A president-elect, Barack Obama, who "believes in strong government and wants to get things under way immediately," said William Leuchtenburg, a University of North Carolina at Chapel Hill professor who's written extensively about the presidency.
• A lame-duck president, George W. Bush, who's leaving office voluntarily. "Bush was not defeated. That makes for an easier relationship," Leutchtenburg said.

This transition lacks the formality — and the coolness — of the last two transfers of power that occurred during tough economic times, the 1980-81 change from Jimmy Carter to Ronald Reagan and the 1993 end of George H.W. Bush's term as Bill Clinton took office. Both new presidents then had defeated the former ones.

Monday gave a vivid illustration of the comity that's characterized the Bush-Obama minuet.

Bush had a cup of coffee in midmorning with Treasury Secretary Henry Paulson to discuss the government's decision Sunday to help ailing banking giant Citigroup. Later, on the steps of the Treasury building, next door to the White House, Bush assured the nation that Washington was ready to take similar action to help other financial institutions.

His statement took only two minutes, but it included this paean to his successor: "I talked to Obama about the decision we made. I told the American people, and I told the president-elect when I first met him, that anytime we were to make a big decision during this transition, he will be informed, as will his team."

About an hour and a half later, Obama unveiled his economic team at a Chicago news conference and mentioned that he'd spoken to Bush and Federal Reserve Chairman Ben Bernanke earlier Monday.

It's not unusual for presidents and successors to talk and consult each other, particularly about crises, though the shared spotlight this time takes that to a whole new level. In December 1992, the George H.W. Bush White House briefed CIinton on its plan to send American troops on a humanitarian mission to Somalia, and the president-elect issued a statement commending Bush for his "leadership." That's more typical.

The troop presence would prove to be an embarrassment for the Clinton White House in 1993. After 18 U.S. Army Rangers were killed and soldiers were dragged through the streets of Mogadishu, Clinton began a troop pullout; all U.S. forces were out by 1995. Osama bin Laden later said that the U.S. withdrawal encouraged his al Qaida forces to plan new attacks.

Some transitions have been downright icy. After the 1932 election, as America continued to reel from the Great Depression, incumbent Herbert Hoover tried last-ditch initiatives but incoming President Franklin Roosevelt refused to cooperate.