Obama said he would have done two things differently in his handling of the recession, including explaining to the American people "it will take a while to get out of this."
"I didn't realize the magnitude of the recession … until we were fairly far into it," he said. "I think the American people may not have been prepared for how long it would take [to emerge]. I take responsibility for that."
The second was housing, which Obama characterized as "stubborn" and hasn't "bottomed out as we expected."
Asked if he'd raise the debt ceiling by executive order if Congress doesn't approve to raise it by the Aug. 2 deadline, Obama said he didn't think the situation would come to that.
Congress is supposed to approve the amount of debt the Treasury Department finances for the U.S. deficit, but "what's happening now is that Congress is suggesting [it] may not vote to raise the debt ceiling," Obama said, which some quarters say is unconstitutional.
"This is something we shouldn't be toying with," Obama said. "The notion that the United States is going to default on its debt is just irresponsible."
Obama kicked things off by posting a question about what costs he'd cut and what investments he'd keep to reduce the deficit.
"I think it's important to get the whole country involved in making determination about programs" that help the economy and the country grow and which programs don't, Obama said, adding that was a debate that would be "heating up" over the next two weeks.
House Speaker John Boehner also got a question in, asking Obama, in essence, where are the jobs.
While calling the post from the Ohio Republican a "slightly skewed question," Obama said Boehner was correct that job growth is too slow.
Two million private-sector jobs were added during the past 15 months, Obama said, but "when you've got an 8 million [job loss] hole," such advances seem small relative to the need.
He said he's worked with Boehner and Republicans on several job-creating issues, such as passing a payroll tax cut designed to encourage spending and improve the business climate.
Concerning taxes, Obama said he thought the American people backed his desire to return tax rates for the top 2 percent of taxpayers to levels before tax rate cuts enacted during the President George W. Bush's administration.
"We need to have a balanced approach where everything is on the table," including closing corporate loopholes, reduce defense spending and looking at entitlement reform, Obama said.
"People have to put their dogmas … and sacred cows aside and come together" to reduce the deficit but still make investments that will advance the economy and the country, Obama said.
Asking "millionaires and billionaires" to pay a little more in taxes to ensure growth "doesn't seem that unreasonable to me," Obama said.
"We can't close the deficit and debt if we close things like Head Start and Medicare … and say to millionaires and billionaires, 'You don't have to do anything.'"