More than 20 of the world's leaders gathered at the White House last night at the start of a two-day emergency summit on the global financial crisis that will continue in five hours of policy discussions. But even as participants began to assemble in what is the largest collection of presidents and prime ministers in almost a decade, doubts were raised that it would achieve anything beyond immediate moves to stimulate the world economy and an agreement to meet again.Economists warned that hopes   read more »