I was first trained as an economist at an Ivy League School, and on that level I can see how it makes perfect sense simply by reading the excerpt and using my imagination to come up with an assumption or two.
I then studied Thomistic-Aristotelian Philosophy at a Seminary, learned the difference between a good and a bad argument, and on that level, I’m with you engineers in terms of demanding proof.
That said, I am extremely skeptical about your claim that this study ranks at the top of the piles of crap. There are enough studies that not only have no evidence to support, but ignore all the evidence that ought to be considered because it goes against that I’d think one of those must rank higher.
While I am very dubious about proof, this may be defensible as a theory.