[epistasis]

What "focuses" jobs in one area though? Is it a conscious choice to place a job in a location, or is it the density of the people and the skills that allows the jobs to exist at all?

The idea that jobs can be placed anywhere flies in the face of pretty much every single city's economic development efforts over the past few decades. It's not realistic, or reasonable.

What can be placed anywhere is housing. The only reason that we don't have higher density is a small number of landowners lobbying to keep everything identical to the way that it was when they moved in, and when they moved in they had just massively changed the landscape from fruit groves to suburban sprawl. They said: change to allow me, but no more. And now they benefit massively by restricting density around them.

[taysic]

If you’re talking about Silicon Valley that was converted from fruit groves to sprawl and a job center then how was that the result of density? In terms of density it’s not much different to many areas.

The focusing is done due to a whole host of reasons but certainly encouraging jobs to spread out is not a bad idea for a number of reasons - including having options and livability

[DataWorker]

People usually cite network effects, or more simply the VC and big money people live in sf and nyc and prefer their workers live there too. How many billionaires live in Boise?