Lately I've been acutely aware of living in an apartment building, thanks to the noise (some of it, alas, my own) and a number of fire alarms going off in the middle of the night. But I still prefer communal living to having to worry about gophers in the driveway and snow on the roof. And most of my friends live in multi-family dwellings -- apartments, condos, and two-to-three-family starter homes that allow you to collect rent to go toward paying the mortgage.
A little more than one-third of all residents in Massachusetts live in multi-unit housing, second only to New York (see all the states' data after the jump). But what's common here is pretty weird in the rest of the US. Only 20% of all Americans live in multi-unit housing, and the number is as low as 8% in West Virginia. And my guess is, when that number is lower than the poverty rate (which is 18% of the entire population in West Virginia, compared with 15% nationally and 11% in Massachusetts), pretty much everyone with shared roofs are poor. Which must make the idea of voluntarily living above or below other people seem even weirder.
Apartment dwellers are commonplace in TV sitcoms, but American politics has a bias toward homeowners (think of the tax deduction for mortgages). The map above shows an extremely theoretical Electoral College majority of states with the highest shares of people living in multi-unit housing. What's interesting is that Florida and Texas are more urban, by this measure, than the older industrial states of Michigan, Ohio, and Pennsylvania.