In a recent interview in Forbes, Nobel laureate Robert Shiller says that the stock market is not as overvalued today as it was in 2007 — but it’s getting darn close.

“We should already be worried about a steep decline,” Shiller says. “The market is highly priced, but by my standards not quite as highly priced as it was in 2007. The cyclically adjusted price-to-earnings ratio got up to 27 then. It’s 26 now. That’s close, though, and that is a cause for concern. So it might be a time to tilt one’s investments away from the U.S. Don’t get greedy.”

Shiller also talked about central bank policy. He says the European Central Bank’s recent dramatic moves have him tempted to invest more in European stocks. And he offers his take on rising college tuition prices.