While “zombie ideas” isn’t a phrase you often see in farm publications, New York Times columnist Paul Krugman has popularized it to describe a uniquely American political condition.

Zombie ideas, the Nobel Prize-winning economist explained in a 2018 column, are,” ideas that should have died long ago, yet still keep shambling along, eating politicians’ brains.”

That column’s title, “Trump and Trade and Zombies” was a pre-tariff takedown of how deeply discredited ideas — like the White House’s belief that trade deficits were bad and import tariffs were good — resulted in its “trade-wars-are-easy-to-win” approach to China.

Zombies or not, trade wars aren’t easy to win, especially when the U.S. ag economy starts with one foot in the grave.

In fact, American ag’s near-sacred belief that it must build export market share by shrinking or eliminating the Farm Bill safety net is itself a zombie idea, argued Harwood Schaffer and Daryll Ray of APAC, the Agricultural Policy Analysis Center, in their Aug. 7 ag policy column, Policy Pennings.

In it, Schaffer, an adjunct professor at the University of Tennessee, and Ray, an emeritus ag professor at the same university, estimated how many, “additional acres U.S. farmers would have to put into production to currently maintain the same export market share they had in 1996,” for corn, soybeans, and wheat.

To come up with that estimate, they compared U.S. corn, soybean, and wheat production and exports from 1996-98 with the same measures from 2016-18. What they discovered was both predictable and astonishing.

For example, “U.S. corn accounted for 68.6 per cent of world exports in the 1996-1998 period, declining to 35.3 per cent in the 2016-2018 period.” In short, American farmers owned two-thirds of the global corn trade in late 1990s but clung to a little more than one-third 20 years later.

What that means, figures the Tennessee team, is that for U.S. farmers to have maintained their respective, late-1970s global market share for corn, soybeans, and wheat, they would need to collectively plant 114 million more acres of the three crops today, a near impossibility.

The reality has yet to alter American farm policy gospel that preaches, “lowering the U.S. price will increase or at least maintain export market share.” That was the goal of the 1985 and 1990 Farm Bill and when both failed, we doubled down and adopted the 1996 Farm Bill, the pair argued.

None of it worked. The U.S. share of the global corn, wheat, and soy markets fell under all those bills. In fact, for 40 years no export-directed ag policy has interrupted the U.S.’s almost constantly shrinking presence in the global corn, soybean, and wheat markets.

But, “Even with these results, many ag economists and politicians continue to repeat the zombie idea that lower crop prices will increase the share of U.S. corn, soybean complex, and wheat markets,” write Ray and Schaffer.

Which make the Tennesseans wonder, “How much contrary evidence will be required to finally vaporize this zombie fantasy?”

Most TV-zonked zombie hunters know the answer: Evidence doesn’t matter because zombies aren’t real; they’re purely fictional.

Like much of today’s U.S. ag trade policy.