But nor does it account for large areas of Manhattan occupied by office buildings (space the residents are not now using), or the very large number of non-residents who came to Manhattan daily (mainly to the office buildings), but not now. Nor does it correct for the pretty large areas of Queens, which has ~1/3 the nominal population density of Manhattan but a death rate around twice as high, occupied by cemeteries and warehouse districts, and so on. Obviously vulnerability to disease is not a simple function of nominal population density, but at the same time population density is almost surely a major factor when comparing to places where the density is far lower, and especially where people travel mainly by car.
And common measures of population density are absolutely resident population divided by land area. Only some rare specialized calculation would count floor space of apartment buildings, or include daily visitors.
IK don’t think the point is clear enough. What TemporalFix is saying is that having 600 people in a one acre lot seems like a high density but is mitigated by the fact that those people are not actually occupying an acre; because each floor is its own area, the living space is actually far more than an acre. A building that is twenty floors high effectively has twenty times as much space as the land area would suggest, and it seems unlikely people sneezing in their apartment on the 15th floor will sprayt it on people on the 4th floor.
Precisely how this affects the epidemiology, though, I don’t know. It seems obvious that people in different floors of an apartment building still have more contact (elevators, shared spaces) than people living in different detached homes, but I’m just guessing.
It has to be borne in mind that New York City isn’t the only big city in America. It’s the biggest and, if one excludes Staten Island, the densest, but there are some other big-ass cities with dense areas, and none of them took it in the ass the way New York did. California has a lot of big cities, and San Francisco is very densely populated, and yet it has gotten off shockingly lightly; unless there is some kind of reporting issues, the entire state has had fewer than 2000 deaths, a stunningly low number given its population, heavily populated cities, and early exposure.
That’s how I read it, too, but I don’t understand the point. Dense cities make for crowded elevators, sidewalks, and transportation, regardless of how many floors a building has.
Another point about NYC relying on mass transit is that its system never closes. Many other large cities’ metros do shut down for 4 to 6 hours. Not so NYC.
I lived in NYC in the early 90s, and we visit semi-regularly (average 1-2 visits per year). Speaking of Manhattan vs the other boroughs (which I don’t usually visit): Car traffic is so insane there and parking is so expensive if you do have a car that very few residents have them. For shorter distances, you are absolutely better off walking than attempting to drive. For longer distances the bus won’t be any faster than driving but you’re paying 3 bucks versus the relative cost of your own car and someone else is dealing with the driving; the subway WILL be faster. You’re never more than a block or so away from some kind of transit, either subway or bus. If you don’t use those but choose a taxi instead, well, you’re not as packed in but that taxi has had numerous other passengers in the past couple of hours.
Basically if you need to go more than 10-12 blocks you are going to take some kind of transit along with a few dozen or hundred of your closest friends. You are going to come into close contact with surfaces - swiping your subway card (I think they’re instituting contactless ones but I don’t know how prevalent they are), handrails climbing stairs to/from the subway, etc. even if you’re travelling during off hours where there aren’t as many riders.
If you’re among the wealthy few who actually do own a car, you’re still going to encounter other people and surfaces because you’re almost certainly in a building with an elevator (or at least stairway access to the outside).
So all in all, as others have noted, you are NEVER far from other people and unless you never leave your apartment, you will spend some time in close proximity either with other people, or with surfaces that other people have very recently been in contact with. Here, in car-based suburbia, my encounters would be: household members and co-workers; even in cubicle-farm hell I’m a few feet away from everyone, I just have to worry about things like building bathroom doors as far as surface contact goes.
As far as health: Obesity by countyshows that Manhattan (New York county) has the lowest rates in the state. Westchester (where one of the super-spreading events occurred) is next, then Kings (Brooklyn). Manhattan’s low rate doesn’t surprise me: you have to walk to get anywhere, if only a block to the nearest bus / subway. So there’s a built-in minimum level of activity for everyone, that I suspect is higher than for suburbanites who drive anywhere. I have to make time to go for a walk. If I lived in NYC, walking is built into my day.
It would be interesting to see how those obesity rates have changed after things settle down. Certainly activity rates will be lower (here’s an opportunity for data mining from Fitbit, Garmin et al).
From my own experience: yep, yep, yep. My office space wasn’t any worse during my stint there, but to get to that office I had to ride an elevator in my apartment building (all those buttons - yeccccch) and another in the office building. The grocery store was a lot more crowded - I can’t imagine trying to maintain 6 feet distancing there. Once you’re at home you’re OK - but apartments tend to be smaller there, so if you’ve got a roommate, it’ll be harder to maintain distancing even at home.
Walking around town is going to be tricky too. If you’re in a popular part of town, there are a LOT of other people near you even as you’re moving around. There isn’t enough space for you to veer wide of each other.
True enough about the other dense cities but I’d want to see how San Francisco’s statistics re use of transit vs cars, and percentage of residents in high-rises compares to NYC. I haven’t spent enough time in other such cities (Boston comes to mind) to get a feel for that; some areas of Washington DC might come close but I suspect car ownership is far more prevalent.
Read that article I posted upthread; it says that New York had something 100 separate “patients zero” who came from Italy and elsewhere in Europe well before their lockdown, while California had 8 from China before theirs, and California locked down earlier.
So all else being equal, with 100 separate points for the virus to exponentially multiply from, it makes good sense that NY would have a LOT more cases a lot faster than California with 8 introductory patients from China.