Thinking about your topic, I wonder if there might not be something different about the educational system in Minnesota (whether official curriculum or at-home instruction) that can help account for that. After all, one of the major whines about why Americans are like they are financially is that they've never been taught any better. Maybe Minnesotans do get taught better.
(Your post title attracted me because, in one of my earlier lives, I was an Experian branch manager.)