California Is Densifying
- William Fulton
- Sep 8, 2021
- 3 min read
Without exception, California’s metro areas are becoming more dense. And the bigger they are, the faster they are densifying.
At least that’s the conclusion of one of the nation’s most astute urban growth economists, Jed Kolko, chief economist at Indeed.com. In a recent article for The New York Times Upshot section, Kolko declared the 2010s as “the downtown decade,” because overall urban densities went up between 2010 and 2020, according to the Census. Kolko made his data available at both the metropolitan and the Census tract level and his statistics found that virtually all California metros densified in the last decade. To understand Kolko’s analysis, you have to understand how Kolko analyzed tract-level data to find the net density or net sprawl. (Warning: This gets pretty nerdy.)
He used what the Census Bureau calls “weighted population density” – or, in his description, the weighted average of Census tract population density (tract population divided by tract land area) for all tracts in the metropolitan area, where the weight is the tract’s share of metropolitan population. In essence, this weighting eliminates the problem created by tracts with no population – or, as Kolko calls it, “the San Bernardino County problem.”
San Bernardino County includes more than 20,000s square miles – more than Massachusetts and New Jersey combined. But much of that land is national forest with nobody living in the Census tracts. In most developed areas of San Bernardino County, people live at typical suburban densities. By giving zero-population tracts a weight of zero in his analysis, Kolko’s analysis can zero in only on areas that are developed.
Not surprisingly, New York was off the charts in density. But the San Francisco metro area – not including Santa Clara County, which is technically a separate metro area – was third, behind New York and just barely behind Honolulu, with about 6,000 residents per square mile. And metro Los Angeles (just L.A. and Orange Counties in this analysis) was fifth nationally, with about 4,200 residents per square mile, just behind Chicago.
