Am I only one who was surprised to see not one reference to any research or proof of his claim? That is, anything that shows a situation where people in, say, equal debt situations, 1/2 were given snowball, half given pay big ones first, then measure debt reduction, satisfaction, perception of accomplishment, etc? Or even just a survey? Anything?

I've heard snowball as a great approach... but without some proof, I wonder if it truly is "...a problem with an obvious but naive solution". Behavioral Economics theorizing aside, even one example from a simple survey or academic study would do much to support his overall point.

Otherwise, his "Many things that don’t look optimal are in fact optimal" comes into question, and I don't want my silly need for proof to get in the way of that essential point, which, come to think of it, I firmly believe even without much proof. But still...