Krugman then told how the ring of mountains almost kept the Challenger Expedition from finding the lost city of Los Angeles

God, this is painful.

Economists trying to understand the rise and fall of regions within a country often rely on some form of economic base analysis. The idea is that a region’s overall growth is determined by the performance of its export industries — that is, industries that sell mainly to customers outside the region, such as the technology firms of Silicon Valley and the Los Angeles entertainment complex (or, here in New York, the financial industry). Growth in these industries, however, generates a lot of growth in other sectors, from health care to retail trade, driven by the local spending of the base industries’ companies and employees.

...

One way to think about this is to say that California as a whole is suffering from gentrification. That is, it’s like a newly fashionable neighborhood where affluent newcomers are moving in and driving working-class families out. In a way, California is Brooklyn Heights writ large.

Yet it didn’t have to be this way. I sometimes run into Californians asserting that there’s no room for more housing — they point out that San Francisco is on a peninsula, Los Angeles ringed by mountains. But there’s plenty of scope for building up.

I'm a huge fan of Paul Krugman. For me, he's by far the best opinion columnist the NYT has. He's a sharp and insightful writer, but like a lot of smart people (see Felix Salmon on the television industry), when he starts talking about something he knows nothing about, his "maybe I should check this" indicator fails to engage. 

1. SF is not part of Silicon Valley; it's around fifty miles away. 

2. People who want to seriously discuss Northern California housing focus on (or at least mention) largest city in the Bay Area, San Jose.

3. Neither the city nor the county of LA is ringed with mountains. We do have some pretty good peaks (the high point in the city is over five thousand feet. Twice that for the county), but they run mainly to the north.

4. More importantly, LA has tremendous scope for building out. That doesn't mean it's a good idea (it's almost certainly not), but LA County has over four thousand square miles of land including tens of thousands of acres of farmland. Add the Inland Empire and we're looking at around thirty thousand square miles. We are not spatially constrained.

For the record, I'm for building up Central LA (much more than Krugman and the rest of the NYT/Vox NIMBYs who favor developments on the edge of the county). I know first hand how bad the housing situation is in LA, but the NYT's take on this has been terrible.