I’m a little late to the game on this one, but last month Joel Kotkin had a widely-panned Wall Street Journal article attempting to debunk what called “the myth of the back to the city migration.” He did this by way of pointing out that the downtown condo markets in Los Angeles, Miami and Las Vegas have been downright abysmal since the start of the housing bust, and just as abysmal as suburban markets, if not worse.

This theory has an obvious, and fatal, flaw: as many have pointed out, those three downtown condo markets are hardly representative of the nation’s urban areas as a whole. The Miami and Las Vegas metro areas were each hugely affected by the housing bubble – so it stands to reason that their respective condo markets would plummet. Los Angeles was not too far behind in that regard.

Still, that’s not the main rub with Kotkin’s argument. As Christopher Leinberger points out, downtown condos are not the only kind of urbanity that exists. This is a major problem in the way that we talk about cities (and suburbs, for that matter). Far too many Americans fail to remember that there are many kinds of neighborhoods between downtown high-rises and suburban tract lawns.

Leinberger draws a different, and quite useful, line: “walkable urban” versus “driveable suburban.” Many driveable suburban areas are in cities, and many walkable urban areas are in suburbs, as he notes. That’s true, but there are many differences even within each category.

Personally, I’ll posit a rather simple classification scheme familiar to anyone who has ever played Sim City: high-density, mid-density and low-density. All too often, we in America forget about the mid-density, which comprises of a large portion of our cities, but typically those beyond the showcase downtown (and so did Sim City’s developers, for a time: the high/low split appears in Sim City 2000, but mid-density zoning does not appear until Sim City 3000. Still, that was 11 years ago, and you’d think Joel Kotkin would’ve heard about brownstones by now). The “mid-density” neighborhoods happen to be my favorite parts of most cities. I have no desire to live in a skyscraper.

Of course, within that, there are even finer-grained distinctions. In New York City, Yorkville and Midtown are both high-density, but quite different. There are also any number of differences between mid-density Williamsburg and Kensington, and low-density Staten Island and Middletown, New Jersey. Still, dispensing with the bright lines separating downtown condo and suburban lawn is a good idea. Cities and suburbs are not static concepts, but ever-changing places.