Not income of their neighbourhood, but the cost of living in their city/state. It needs to be a big enough region that a good job gives social mobility, but int

Not income of their neighbourhood, but the cost of living in their city/state. It needs to be a big enough region that a good job gives social mobility, but introducing California wages into Ohio would cause massive inflation there, driving normal people into poverty. At the same time nobody could live in LA on Ohio wages.