[dustinmoris]

Some of the most expensive places in London are outside Zone 1 (Hampstead, Richmond, Kensington, West Brompton, Wimbledon, etc.). Also creating a high density of social housing aka ghettos is not desirable for any city in the world and those who have it have big problems because of it. London has huge inequality problems, but the fact that you can have a millionaires road only 5 minutes away from a council estate has the advantage that social issues are not just being ignored and brushed under the carpet by forcing people as far away as possible, it creates more diverse and accepting communities, it ensures that people from all different fortunes have access to nice parks, good transport links (which are even more important for people who are on low income), etc.

[systemtest]

I don't think it is very nice to make the assumption that a high density of social housing will result in a ghetto. Do you have sources that people in social housing are more prone to violence and crime?

[karmakaze]

It's neither an assumption nor about being nice. As mentioned isolated dense social housing has been observed to create conditions that alternate plans can counter. It also doesn't have to be about violence or crime--mere the neglect of neighbourhoods that are not 'in mind' of decision makers for simple things like maintenance of roads, lights, etc all contribute to this.

[NLips]

Ghetto doesn't imply violence or crime to me. Per Wikipedia: "A ghetto is a part of a city in which members of a minority group live, typically as a result of social, legal, or economic pressure."