Weary investors waiting for a vigorous economic recovery may have to keep waiting—at least over the short term, said Austan Goolsbee, a former economic advisor to the Obama administration.

Goolsbee, an economics professor at the University of Chicago, told the Vladimirs and Estragons at the 2016 Morningstar Investment Conference on Tuesday that a recovery with higher growth rates is at least 12 to 18 months away, if not longer.

“We have grown at a modest pace for some time, in a way that disproves what the Fed has been predicting,” Goolsbee said. “If we plotted the Fed’s forecast for what the growth rate would be 12 months from now, and we plotted the evolution of those forecasts, they would show you 30 quarters in a row of mistakes of exactly the same form.”

Nevertheless, the U.S. economy is not particularly weak, but slow—only the productivity and entrepreneurship of American workers can reinvigorate growth, said Goolsbee.

“The Dow is at 18,000. How is that possible?” Goolsbee asked. “It’s because the innovative capacity of we, the human beings of the world, is unbounded. We’re still an entrepreneurial culture. You have to look around and realize that it could be a whole lot worse.”

While Goolsbee said there was nothing structurally amiss in U.S. markets, he did say that investors should stop waiting for a sudden return to the halcyon days of high returns that occurred before the global financial crisis.

Goolsbee criticized the Federal Reserve and other economists for having unrealistic expectations for the U.S. economy.

“The Fed comes out with an economic forecast and each quarter they give a different reason for not meeting their forecast,” Goolsbee said. “When they’re wrong, they say they didn’t know the winter was going to be more mild than they thought it was going to be. How could they know there was going to be a Japanese earthquake. Now the British are leaving the EU. Eventually you have to decide that their forecast model is broken.”

The reality advisors and investors must face is that there is no hero who is going to resuscitate the moribund economy, said Goolsbee.

For one thing, the ability of monetary policy to impact economic growth is limited, he said.