re: Relative poverty is also a form of poverty.

There was a recent thread[1] on twitter by Noah Smith on this topic, related to a study[2] that suggests that a) relative life satisfaction tends to correlate with their relative ranked income and that b) upward comparisons matter more than downward comparisons.

From those premises, Noah Smith appears to be arguing that high inequality has a negative impact on overall happiness.

[1] https://twitter.com/Noahpinion/status/969676076912750592

[2] http://journals.sagepub.com/doi/abs/10.1177/0956797610362671