In the ever-lasting debate over sprawl, the most enduring argument centers on the definition of sprawl itself. The latest entrant is, perhaps, the oldest entrant: density. 

As reported by Richard Florida in his CityLab column this week, NYU doctoral student Thomas Laidley has introduced a new method to measure sprawl. Laidley's "Sprawl Index" uses the following methodology: 

"Laidley uses these aerial images to estimate sprawl at the Census block level, the smallest level available, estimating the share of metro population in those blocks below three key thresholds: 3,500, 8,500, and 20,000 persons per square mile. His index is based on the average of these three values, with higher scores reflecting higher levels of sprawl."

Laidley essentially posits that density and sprawl are inversely related. And by "posits," I mean he makes a circular argument, in which he defines sprawl according to the things that he thinks define sprawl. 

From this, Florida reports that it has the highest overall density of any metro in the country, Los Angeles isn't actually sprawling. He notes that "the biggest surprise" is that Los Angeles is the "least sprawling metro in the country," in part because it is so dense. Interesting, sure. But I'm not sure how surprising it is. Really, it's surprising only if you don't read much Richard Florida

In fact, that density figure has been reported and debated for years, not just by Richard Florida but by plenty of others (hereherehere). Then, as now, it's important to note that measures of density depend mainly on how you define a given metro area. You don't need a spreadsheet to know that L.A.'s urban core is not more dense than Manhattan or San Francisco. Those metros just include a greater share of vacant and low-density land than the L.A. area does. Density is a mathematical trick, and a crude one at that. 

The real reason why Laidley's project is doomed to be disappointing, if not outright misleading, is that sprawl is by definition a subjective notion. Density may be quantifiable. But sprawl is a qualitative matter. Though his heart is in the right place, Laidley is using the same modernist objective approach as did the 1950s planners who got us into this mess in the first place. 

For better or worse, sprawl entails judgment of value and aesthetics. Some people use it as a pejorative; others think those people are being fussy and effete. A new "index" isn't going to settle that argument. 

Granted, critics of sprawl probably agree that low densities often correlate with sprawl. Certainly the types of urban neighborhoods they prefer require high(ish) densities. But density is not enough. My own neighborhood is plenty dense. But I can't walk to the end of the block for a carton of milk, and I can't take a bike ride without taking my life in my hands. At rush hour it can take an hour to drive five miles. That's not sprawl, I guess. But if sprawl is bad, then whatever LA is certainly isn't good. 

The evaluation of sprawl and non-sprawl entails, most importantly, questions of efficiency, diversity, design, walk- and bike-ability, and a whole other range of aesthetic considerations. And let's not forget the origin of the word sprawl. Sprawl is a spatial concept. It refers to territory. Any urban area that covers 13 areas codes, five counties, and thousands of square miles -- where you can't see one end from the other because the horizon gets in the way -- is sprawling. Any metro where regulations and financing mechanism encourage the paving over of farm land and wilderness is sprawling. Any metro that has dying tract homes on its edges is sprawling, regardless of what is going on in the center. 

I guess I don't care how neatly a regression model, using data captured from 30,000 feet in the air, can work out when so many places before my very eyes so ugly.

The quality of a city depends at least as much on the quality of neighborhoods and blocks as it does to the functioning of the region as a whole. Density and good urbanism in one part of a city does little for the people in the other parts. We can't look at Los Angeles, or any other high-density metro, and say, "Great! It's dense. Our work here is done." 

In other words, density is not an end in and of itself.

Density in L.A. presents an opportunity, and a tremendous one at that. It's an opportunity to take all the people, buildings, capital, and spirit that are crammed in here at 6,100 people to the square mile and figure out how to design our buildings, transportation network, public spaces, and civic life in a way that makes the most of what we have. 

That index tells us that we're No. 1 at density. So what? Let's be even better at something else.