Residential neighborhoods don’t have the same peak density. In central business districts every street has shops, in residential ones it wouldn’t be sustainable.

Much of the world proves this assumption false. See, e.g.:

- Residential districts in China and many former Soviet countries. Big concrete blocks, with the bottom floor lined with small stores. They're absolutely delightful places to live.

- Urban residential districts in the US aren't quite in this style, but a city like Cambridge will have small shops within walking distances of virtually all housing.

The critical thing is that the shops are a lot more pleasant and human than US business districts. A massive lunch hour line at some overpriced (probably due to high-rent and long lines everywhere) sandwich place isn't very human. A small business run by the owner is. One of the differences is that in residential settings, business owners and residents are part of a community -- they get to know each other, sometimes for decades. Business districts have people moving in and out too frequently for that.

"Peak density" is also a lot worse than "mean density." Both a customer and a business owner is better served with traffic spread out throughout the day, rather than nearly 100% of business crammed in during breakfast and lunch hour.

> a city like Cambridge will have small shops within walking distances of virtually all housing

I lived in Cambridgeport near Central Square in Cambridge, MA. There was indeed a small convenience store/variety shop almost within sight of my apartment. In six years, I bought something from them only once that I can recall. I used to walk quite literally past them to Whole Foods to save money. (When Whole Foods is killing you on price, you’re going to have a tough go of it.) Looking on Street View now, there’s paper over the windows and a notation of “permanently closed”.

I’m in a different neighborhood of Cambridge now. There are local shops here as well. Except for the food places, most are empty of shoppers almost all of the time. I don’t know what’s different to make these shops not particularly useful, but most purchasing seems to happen at the larger supermarkets and big box stores a few miles away (or online). Those have better selection, much better pricing, and are faster/more convenient in aggregate.

I don’t blame the local stores if they have to set uncompetitive prices due to rent or whatever other factors, but consumers also don’t have to buy products at uncompetitive prices.

For grocery shopping in Cambridge, I'd be some combination of Whole Foods, Trader Joe's, and H-Mart. Yes, there are a few specialty markets and bakeries but those are almost certainly occasional things. CVS pharmacy. Maybe a hardware store if I need something routine and small. And restaurants of course. But besides buying consumables, mostly food and mostly at bigger chains, I'm not sure what all the small stores I'd be going into would be.

I remember when shopping meant visiting the butcher, bakery, fruit market, dairy. Then supermarkets were invented.

But everything that is old is new again. Now we shop at three different supermarkets! To get the best prices or quality or specialty item or whatever.

Maybe they'll invent a super-duper-market or something like that next, and we'll go back to a one-stop experience.

> Residential districts in China and many former Soviet countries. Big concrete blocks, with the bottom floor lined with small stores. They're absolutely delightful places to live.

That really isn’t true. At least in China, the most common living arrangement in big cities is the gated apartment complex, their might be some retail on floor one, but it is usually on the other side of the gate, and the gate you can enter or exit from is often not conveniently located to access that retail easily (given my experiences living in Beijing). If they did away with the fences/gates, things would be much more convenient.

I live in a rural/suburban town of a few thousand. There's a tiny "downtown" thing branching off the highway with a deli, convenience store, pizza place, and some other small stores. Whole town is only designed for cars besides some sidewalks in this downtown area, but you can bike around just fine if you're fit enough for hills or have an ebike. I have a single family home that's about a 10 minute bike ride from this downtown. Almost all homes are single family, and a lot of farms. I think this setup works great.

excellent comment!

Hmm, comparing flourishing residential neighborhoods in Berlin like Kreuzberg (not every but enough streets have small shops, Cafes, Restaurants, all vibrant and positively living from sunrise to sunset and beyond, enjoyably walkable with a lot of green) vs the more purer City-center office regions like Mitte where you have shops that noone needs (yeah yeah sure someone wants to buy at Dolce Gabbana, biased not me) which just feel awkward beyond usual business hours I find this generally not true.. atmosphere is much more desirable here, and its better for the "small shops" vs Starbucks&McDonaldses also..

Sure, if you think only of residential one family house areas (but which true city centers have those) or poorer skyscraper suburbs that is true, but another story?!

Mixed use zoning is the answer. The American-style segregation of life vs. work needs to be a thing if the past. It might have made sense when most of work was industrial and thus noisy and dirty, but with modern office environments and services it just adds mobility costs.

The difference in perspective in this thread boils down to North American (except NY) vs. European perspectives. My residential area has six floor buildings with lots of residents and ground floor shops and cafes. This setup only rarely exist in the US.

> Residential neighborhoods don’t have the same peak density

This is only true in American suburbs. You have horrible one family dwellings only, and you space them far out on empty sections with massive roads between them.

This is the problem, and its also what is actually unsustainable.

The reduced density is still enough to support mini-hubs.

In Europe they are common and have been flourishing again even as cities flounder.

Pre pandemic my local town center in the London commuter belt was in a death spiral. Now its expanding.

Of course they would and they are.

I grew up in a district which has 150k inhabitants and an effective population density of 4.6k people per square kilometre (11.8k people per sq mile) and it was much like a city within a city, with all the shops, services etc. Everything within walking distance.

It even has somewhat of a regional identity and a political movement which capitalizes on that.

To this day I see it as the sweet spot of population density - it's dense enough for the things you mentioned, but at the same time doesn't feel crammed.