It's an interesting suspicion and cool in a Freakanomics way, but it apparently lends little predictability.

From your article:

> But the South continues to lag behind the rest of the nation economically, with seven out of the 10 poorest states in the U.S. located there. And while stereotypes are fading, many outside of the region continue to look down on it. “When I told my family I was moving to Houston, it was like I was leaving for a leper community—they wanted to have a funeral for me,” Hotez says. “My in-laws certainly have perceptions about this being a backwards place, not realizing that some of the most sophisticated universities in the world are located in the South.”

They link to the bottom 10 states by poverty level. In fact the bottom 12 states for poverty level are in the South:

https://en.wikipedia.org/wiki/List_of_U.S._states_and_territ...

If hookworm was the cause and hookworm was solved, why are the states still so poor?

Or why don't they have University degrees?

https://en.wikipedia.org/wiki/List_of_U.S._states_and_territ...

I'm reminded of Massachusetts's Old Deluder Satan Act of 1647. Which required cities and towns to fund public schools.

https://www.mtsu.edu/first-amendment/article/1032/old-delude...

My offhand thought is for long standing cultural and historical reasons the leadership in southern states doesn't care about poor and working class education. Primarily you don't need to read to able to pick tobacco and cotton. Quite the reverse. Some places it was illegal to teach black people to read and write.

Where in the north the religious culture and industrial economy made it imperative that workers be able to read and write. Can't read, can't read the bible, surely will fall into the hands of Satan. And they'll use the wrong type of oil on a machine and wreck it.

Imagine you have two runners who are running a marathon. The first runner has to carry a 50 lb backpack for the first 10 miles of the race. If you check their times for the midpoint of the race would you say carrying the backpack can't possibly be the reason the first runner is slower than the second? They aren't carrying it anymore (ie the problem is solved) so why didn't they catch up?