I disagree for two reasons. 1) What is mobility? The ability to move out of the lowest income group? How easily does that happen? If it's quick and easy, why d

I disagree for two reasons. 1) What is mobility? The ability to move out of the lowest income group? How easily does that happen? If it's quick and easy, why doesn't everyone do it? And what about the reverse? How easy it for a person to move from a median income back into the lowest income. I think the idea of mobility is used as a reinforcement for the protestant work ethic / American dream sort of delusion that says "poor people can just work harder and save more and they won't be poor any more". But we have an enormous amount of evidence that points to that not being the case. 2) Also, you haven't provided an argument for why income inequality isn't a problem. If the lowest earners have extremely limited access to housing, healthcare or education, such as is the case in the U.S. I think that's a problem.