Ok, so what in the 21st century could lead a stock market to the worst December since the Great Depression year of 1931?

Let’s start by saying I have always liked Fed Chair Jay Powell’s pragmatic image. I only hope I wasn’t fooled.

He has the ideal experience mix of Washington finance and private sector, so he ought to be able to tell the forest from the trees.

But last week’s Fed meeting was even more disastrous than the one in September.

Since the September meeting — when the Fed hiked rates because the economy was displaying “strong labor market conditions and a sustained return to 2 percent inflation” — stocks have sold off.

Then came Wednesday’s meeting, when the Fed hiked again despite all being well in the economy.

With good growth, good employment and no inflation to speak of, this hike sent the market spinning into a state of disbelief. The market closed down 352 points, and Thursday subtracted 464 more.

This correction is now all on the Fed. It over-reached just like virtually every other academic Fed, combating Ghosts of Inflation Past that haven’t appeared in decades.

Powell needs to expand his Rolodex to include more than just policy types and start speaking with some real-world practitioners.

For example: FedEx CEO Fred Smith. If there’s anyone who would have a read on the pulse of the economy, he’d be it. FedEx’s stock is down 40 percent since September.

Or chat with ExxonMobil CEO Darren Woods. His shares are down 22 percent since the end of September. Oil itself is down from $76.41 a barrel on Oct. 3 to $45.88 on Dec. 20. That’s a 40

percent drop.

I think it’s time to ask what Powell is thinking.

If and when inflation rears its ugly head — which it hasn’t done in 20-some years — a rate raise or two would eradicate it quickly.

It’s time for Powell to stop chasing ghosts.