After investigating the definitions of "suburb," I was thinking about Feargus O'Sullivan's description of "urban" London. There were three simple characteristics: proximity to the center of London, density and noise. All the other "urban" characteristics were either signs of (a) gentrification (coffee bars; vintage stores; sidewalk cafes; hipster bicycle culture; independent designer boutiques; high-rise, open-plan apartments) or (b) poverty (subsidized housing).
Here in New York City, we have the same signs of gentrification, but poor people can and do live in privately owned, usually rent-stabilized, apartments throughout the city. We have many dense, noisy neighborhoods that are not particularly gentrified. O'Sullivan seems to equate "urban" with gentrified, and that makes me wonder whether there are any neighborhoods of London left ungentrified.
In New York you can certainly find hipster coffee bars in most neighborhoods of Manhattan, Brownstone Brooklyn and Western Queens, but there are a lot of dense, transit-accessible neighborhoods that still don't have them. Last I checked that included Crown Heights and Flatbush, as well as Sunset Park and most of Corona in Queens. Most of Jersey City, Elizabeth and Newark are pretty low on the vintage stores, as are western Yonkers and southern Mount Vernon - though of course they have thrift stores. And of course, most of the Bronx between Fieldston and the Bronx River is dense urban development, and I'm not sure there's even a coffee bar in Riverdale. That means that probably half of the urban area of New York is still ungentrified.
I haven't spent that much time in London, and what time I have spent there has been in areas that have not been poor in recent memory. I didn't see any housing projects around Buckingham Palace or the Houses of Parliament, where the homes of the literal gentry have historically been. I did take a stroll through Peckham on my last visit and didn't see any gourmet cafes, but I wasn't looking that hard. So those of you who know London better: are there large gentrifying populations in every dense inner neighborhood? Are there notable exceptions?
If not, I wonder how much of it is due to the way London subsidizes its housing. Is there rent stabilization, or is it all done through "council flats"? Does that create sharper segregation?
I'll have more to say about this in the future.