Meanwhile, Americans are not saving enough for retirement, which is a bigger issue than tax policy, Fink said.
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Bonds are no longer providing sufficient returns, Fink told "Squawk Box," because longer life spans are making retirement income even more crucial.
"We are going to have to start thinking about ways of creating a different type of mandatory savings policy," he said, pointing out that "the average American only has $25,000 of savings."
He added, "Only 65 percent of Americans, who can participate in a defined contribution plan, participate."
Social Security was never meant to be a savings plan, Fink reminded. "Even the highest earner only receives $24,000 from Social Security, and yet 70 percent of Americans' income during retirement comes from Social Security."
"There's a duration gap between what we are putting into our pensions in terms of maturities and what our actual needs are," he said. "You're not going to want to get your duration in 30-year bonds today at a 3 percent rate."
"I believe you are going to get duration through equities," Fink concluded, emphasizing his bull case for stocks.
_ By CNBC's Matthew J. Belvedere. Follow him on Twitter