But he thinks the end result should have U.S. revenues at 18.5 percent of GDP and expenditures at 21 percent.
Those levels would be "sustainable" because the ratio of the nation's national debt to GDP wouldn't increase, and might even fall over time, as economic growth makes up for the revenue gap.
The Berkshire Hathaway CEO said the "fiscal cliff" is having no effect on his long-term investing decisions.
He repeated his call for a minimum tax rate for the ultrarich, saying the small minority that don't pay any taxes at all are among the "moochers" Mitt Romney referred to in his "47 Percent" comments.
Buffett argues that many middle-class people are unfairly burdened with payroll taxes for Social Security and Medicare, calling it the "most regressive" tax. They only apply to income under a cutoff just above $100,000 but generate $800 billion a year, one-third of U.S. revenue.
He rejected Joe Kernen's suggestion that payroll taxes should not be part of the debate because they're for an insurance system. With a laugh, he said, "Believe me, it's a tax on income."
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