I think many economists have expressed concern about wealth concentration. You don't need to be a socialist to be concerned. Personally, it isn't likely to affect me or my kids. But sometimes one must think beyond the boundaries of one's family and recognize that the long-term effects of wealth concentration is slavery.
There is a group that is in the .01 -.001%. Kind of what I would call wealth concentration. It seems to me that a large percentage of those people are liberals. There are some that would be more conservative.
I would guess that in the US it is more of a bottom heavy bell curve, however there is access to moving up or down the curve. How would you even the wealth curve?
The other countries that you speak of are none of our concern. If they take advantage of our advancements that is good, if they oppress their people that is their business. We should not be attempting to tell them what to do.