A prolonged period of tepid economic growth will negate any need for the Federal Reserve to raise rates well into the future, former central bank governor and Columbia University economics professor Frederic Mishkin told CNBC.
"We're going to have a tremendous amount of slack in the economy for quite a number of years," he said. "If there's still a lot of slack there's no reason to raise rates. In fact, it would be a big mistake."
