This substack post expressing mild skepticism about COVID-caused decline in superstar cities was excellent, but! I think Noah draws on economics in a couple of places where it's ossified into a sort of conventional wisdom. So below are a couple of pushbacks/questions: https://twitter.com/Noahpinion/status/1354127530039500800

Starting with knowledge spillovers. Urban Econ has been pretty firm that clustering matters for innovation, but not enough people are asking a basic, first-order question: if people are more urbanized, educated, and clustered than ever, why are the Growth Econ people so glum?

Lots of folks are working to answers to why growth is subpar, but there's a disconnect between the Urban and Growth Econ folks (in @tylercowen's sense of questions people are (or aren't) asking).

I should note Noah doesn't take a strong stance on this in his post, but!

A highly relevant paper by @enrico_berkes, @O_Deschenes, @ruben_gaetani, @jeffrlin, and @ChrisSeveren found that 1918 NPIs that reduced local knowledge spillovers did not reduce patenting activity, and in fact, saw higher patenting activity afterwards.

The jury is still out, but it is possible that the innovative benefits of agglomeration are taken too much for granted.

(I'm working on an answer looking at the modern urban/growth disconnect, so if you're interested in this kind of work, feel free to DM me).

Next are cultural amenities. This is somewhat in the eye of the beholder, but, anybody who's spent lots of time out on the road can tell you that pretty much any city of any significant size has been investing over the past decade in amenities pretty hardcore.

You can find a hipster bar or fancy coffee shop in pretty much all cities with 40,000+ people these days. That's not the only metric, but I think the diffusion of a sort of the superstar city "gentrification aesthetic" across the country is really underappreciated.

Third is dating and friendship. Like innovation, this is one of those areas where urbanization, technology, education, and clustering seems to *not* have produced the first-order effects you might have expected.

Noah is bullish on dating, less so on friendship, in smaller cities, but as @lymanstoneky, @DouthatNYT, and others have been relentlessly pointing out: marriage is down and loneliness is up under the current dispensation, particularly among the young.

So at one point are we going to start second-guessing the benefits of clustering? In a very first-order sense, people seemed to be forming friendships and getting married just fine in a less-urbanized, less concentrated world.

I'm well aware of all the housing, poverty, and cost of living challenges in expensive cities (so don't @ me), but: maybe the superstar cities aren't as great for social relationships as we think in ways we (economists) don't really understand well.

So altogether, I'm not ready echo @DouthatNYT's break up the liberal city, but I think econs should be open to the idea that the relative decline of the Bay Area (+ maybe NYC) may not be as bad for efficiency, growth, etc. as the econ lit would have it. https://www.nytimes.com/2017/03/25/opinion/sunday/break-up-the-liberal-city.html