Manhattan and Brooklyn are much poorer than you think. So how can anyone afford to live there?

New York City census data: Manhattan and Brooklyn are much poorer than you think.

(Excerpt)
Measured by median income, Manhattan and (especially) Brooklyn are much poorer than you think. Manhattan’s median annual household income is $66,739, while Brooklyn’s is a mere $44,850. Its less fashionable neighbor, Queens, outearns Brooklyn at $54,373 per year. New York City’s most suburban borough, Staten Island, is also its richest, with a median household income of $70,295, while the suburban counties surrounding New York are all richer than any of the boroughs. Meanwhile, the cost of living is astronomical in Manhattan, where the median monthly rent is $3,100; it’s $2,800 in the gentrifying northwestern quadrant of Brooklyn. So how can so many relatively low-income people still live in these areas? The answer has to do with the peculiarities of New York’s housing stock, demographics, and history. Here are the main seven factors.