Should cities base their density on developed land or developed and undeveloped land?

[missionhome]

The "urban area" statistic takes into account undeveloped areas within a metropolitan area and how it can lower the true density of actual development. An urban area only includes regions with a high enough density in the population.

Here is the definition of an "urban area": Urban areas in the United States are defined by the U.S. Census Bureau as contiguous census block groups with a population density of at least 1,000 inhabitants per square mile (386.1/km²) with any census block groups around this core having a density of at least 500 inhabitants per square mile (193.1/km²).

So in a city with a large lake in it, that area would not be included in the total area. Only developed areas where enough population resides is counted.
The Los Angeles Urban Area is actually the densest in the entire USA. When the undeveloped deserts and mountains that are included in the total land area of the metro are taken out, the developed urban area density is: 7,068.3

Since somebody mentioned Houston, their urban area density is 2,951.1.

List of United States urban areas - Wikipedia, the free encyclopedia