From his earliest days in office, Mr. Bush paired his belief that Americans do best when they own their own home with his conviction that markets do best when let alone.

He pushed hard to expand homeownership, especially among minorities, an initiative that dovetailed with his ambition to expand the Republican tent  and with the business interests of some of his biggest donors. But his housing policies and hands-off approach to regulation encouraged lax lending standards.

Mr. Bush did foresee the danger posed by Fannie Mae and Freddie Mac, the government-sponsored mortgage finance giants. The president spent years pushing a recalcitrant Congress to toughen regulation of the companies, but was unwilling to compromise when his former Treasury secretary wanted to cut a deal. And the regulator Mr. Bush chose to oversee them  an old prep school buddy  pronounced the companies sound even as they headed toward insolvency.

As early as 2006, top advisers to Mr. Bush dismissed warnings from people inside and outside the White House that housing prices were inflated and that a foreclosure crisis was looming. And when the economy deteriorated, Mr. Bush and his team misdiagnosed the reasons and scope of the downturn; as recently as February, for example, Mr. Bush was still calling it a “rough patch.”

The result was a series of piecemeal policy prescriptions that lagged behind the escalating crisis.

“There is no question we did not recognize the severity of the problems,” said Al Hubbard, Mr. Bush’s former chief economics adviser, who left the White House in December 2007. “Had we, we would have attacked them.”

Looking back, Keith B. Hennessey, Mr. Bush’s current chief economics adviser, says he and his colleagues did the best they could “with the information we had at the time.” But Mr. Hennessey did say he regretted that the administration did not pay more heed to the dangers of easy lending practices. And both Mr. Paulson and his predecessor, John W. Snow, say the housing push went too far.

“The Bush administration took a lot of pride that homeownership had reached historic highs,” Mr. Snow said in an interview. “But what we forgot in the process was that it has to be done in the context of people being able to afford their house. We now realize there was a high cost.”