He said the Federal Reserve has done the right thing with it easy monetary policy.
The U.S. central bank ended its latest round of bond purchases last year and now policymakers appear to be on the brink of their first rate hike in nearly a decade. Many economists believe September is the most likely date for liftoff.
Buffett said he has no idea when the Fed might move. "They've fooled me so far. So I've been wrong," he said. "I would have thought by now you would have seen much higher rates than we have now, which is essentially nothing."
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He added that the Fed should stay low as "Europe keeps following the present policies." The European Central Bank has initiated a Fed-style quantitative easing bond-buying program to help boost the euro zone economy.
"If you have negative rates in Europe, I think there a lot of consequences to raising rates significantly here," Buffett said.
More than $2.1 trillion of outstanding euro zone sovereign debt now has a negative yield, according to calculations by Goldman Sachs.