You might dismiss the likes of Mr. Santelli, saying that they’re basically in the entertainment business. But many investors didn’t get that memo. I’ve had money managers — that is, professional investors — tell me that the quiescence of inflation surprised them, because “all the experts” predicted that it would surge.

And it’s not as easy to dismiss the phenomenon of obsessive attachment to a failed economic doctrine when you see it in major political figures. In 2009, Representative Paul Ryan warned about “inflation’s looming shadow.” Did he reconsider when inflation stayed low? No, he kept warning, year after year, about the coming “debasement” of the dollar.

Wait, there’s more: You find the same Groundhog Day story when you look at the pronouncements of seemingly reputable economists. In May 2009, Allan Meltzer, a well-known monetary economist and historian of the Federal Reserve, had an Op-Ed article published in The Times warning that a sharp rise in inflation was imminent unless the Fed changed course. Over the next five years, Mr. Meltzer’s preferred measure of prices rose at an annual rate of only 1.6 percent, and his response was published in another op-ed article, this time in The Wall Street Journal. The title? “How the Fed Fuels the Coming Inflation.”

So what’s going on here?

I’ve written before about how the wealthy tend to oppose easy money, perceiving it as being against their interests. But that doesn’t explain the broad appeal of prophets whose prophecies keep failing.

Part of that appeal is clearly political; there’s a reason why Mr. Santelli yells about both inflation and how President Obama is giving money away to “losers,” why Mr. Ryan warns about both a debased currency and a government that redistributes from “makers” to “takers.” Inflation cultists almost always link the Fed’s policies to complaints about government spending. They’re completely wrong about the details — no, the Fed isn’t printing money to cover the budget deficit — but it’s true that governments whose debt is denominated in a currency they can issue have more fiscal flexibility, and hence more ability to maintain aid to those in need, than governments that don’t.