Imagine two cities, Fortyville and Hundredsixton. In Fortyville, people make an average of $40,000 a year, while in Hundredsixton, the mean annual income is $160,000.
Would you expect the average rent for a room in Hundredsixton to be $10,000/month higher than the average rent in Fortyville? That isn't what happens in practice; rent doesn't go up one-to-one with income.
