I honestly haven't looked into it. I could see it going either way: a systematic error in the IHDI calculation results in nonsense results vs. the USA is extremely shitty for huge swaths of the population in a way that seems counter-intuitive given the general air of affluence/prosperity put on not only by American media, but also its populace (ie, consumption of status items on credit, people on facebook et al making outward displays of stability despite private problems, etc).

The people whose job it is to really look at the problem say reality is a way that I would not have guessed based on my gut reaction. The central lesson of empiricism has classically been that your gut reaction is prooooobably off the mark unless you're intuiting how not to get eaten by savannah predators.