Palin said McCain had sounded the alarm years ago on failed mortgage giants Fannie Mae and Freddie Mac, but other lawmakers had ignored his warnings.
Biden reminded Palin that McCain's early words in the face of the current credit crisis were, "The fundamentals of the economy are strong."
"That doesn't make John McCain a bad guy," he added, "but it does point out he's out of touch."
However, Palin offered an explanation of McCain's much-maligned comments about the economic fundamentals.
"John McCain, in referring to the fundamental of our economy being strong, he was talking to and he was talking about the American workforce," she said. "And the American workforce is the greatest in this world, with the ingenuity and the work ethic that is just entrenched in our workforce. That's a positive. That's encouragement. And that's what John McCain meant."
Biden ridiculed the McCain-Palin tax plan as a measure that would help only the wealthiest corporations and individuals and pledged not to increase taxes on middle-class families who earn less than $200,000.
"Where I came from, it's called fairness," Biden said. "The middle class is struggling. Under McCain, 100,000 households get not a single break in taxes. When you [the middle class] do well, America does well. This is not punitive. McCain wants to add tax breaks for the corporations and wealthy. We have a different value set. The middle class deserves the tax breaks."
Palin said the health of the economy was contingent on allowing the private sector to grow on its own, free of a heavy tax burden.
"You said paying taxes is patriotic," she said. "You're not always the solution. Too often you are the problem. Get out of the way and let the private sector and families prosper."P>
With just two minutes to answer each of moderator Gwen Ifill's questions, the candidates covered a lot of ground quickly. Moving from the economy, Biden and Palin discussed climate change, same-sex marriage and foreign policy.
Though the candidates disagreed on the whether the United States should sit down with the leaders of rogue nations such Iranian President Mahmoud Ahmadinejad, both trumpeted ongoing American support for the state of Israel.
Palin said she supported a two-state solution to the Israeli-Palestinian conflict and the Bush administration's efforts to negotiate a settlement.
Biden touted his own pro-Israel credentials, ripped the Bush administration's efforts, and said he and Obama would push for proactive diplomatic engagement in the Middle East.
Palin, who has built much of her candidacy on her energy policy credentials, called for further drilling and use of domestic oil. She declined to place the blame for global warming squarely on human beings.
"I'm not one to attribute every activity of man to change in the climate," Palin said, arguing for more drilling of fossil fuels in the United States. "People are so hungry for those domestic sources of energy to be tapped into. It is safe to drill and we need to do more of that."
Biden sharply disagreed, saying he believed climate change was "man-made" and the nation needed to actively seek alternative energy sources.