A long time ago, I had to take an ethics class to get my Computer Science degree. One of the things that came up in the papers about calculating the statistical value of a life was that people care more about being more prosperous than their peers than absolute material wealth.
I think about that a lot: its not about material wealth, but status, something that if someone has more of you have less of. A lot of people are invested in their status in various communities, and are afraid to lose it or have it become meaningless.
I don't know what to do about that; no matter how wealthy we all are people are still going to want status.