- more traffic: compare to now? or pre-COVID? because now it is already lower than pre-COVID, at least in SF. I have lived here for more than 20 years, and only now I see seeing empty parking spots around my house. I would never see this 10 years ago. So, if we double the population, yes there would be some additional traffic. But how would it compare to 10 years ago ?

- more noise: From traffic? electrification is making transportation quieter than before. From people in the streets? again the streets are way less busy compare to pre-COVID at least in SF. People either do not work, or work from home, get delivered everything from movies (Netflix), to food (UberEats) or shopping (Amazon), etc. foot traffic is WAY lower than pre-COVID. So if we double the population, yes there would be some additional foot traffic. But how would it compare to 10 years ago ?

- more pollution: From traffic? electrification is offsetting some of it. From trash, well those people were trashing elsewhere too.

- more anonymity, crime: That is cultural. Tokyo is fairly dense city, and with fairly low crime compare to US standards.

"The people who benefit most from higher density tend to be young professionals": Go visit a major city in Europe (Paris, Barcelona, etc) that has high density, and you would see lots of different generations, not only young professionals. It is possible to live from cradle to grave in those cities. It does not have to transition spot when you are young, professional and looking at dating. It could be where you go to kindergarten, up to university, work and retire.

I feel like the main thing that NIMBY fear is change, any change. Hausmann, where are you ?

>I feel like the main thing that NIMBY fear is change, any change.

Broadly disparaging large, diverse groups of people like this is what makes things harder, not easier. This is tribalism.