If you generally agree with me that anti-density restrictions hurt cities, you should read The Gated City by The Economist's Ryan Avent. If you generally disagree with me that anti-density restrictions hurt cities, you should read The Gated City to see why you are wrong.

Ryan's central thesis is that tight growth restrictions in the highly-productive coastal markets have inflated housing prices there, driving people to less productive but cheaper parts of the country.  Local zoning decisions, when aggregated, reduce innovation, dampen productivity and sap our wealth.  Micro decisions have macro effects; there are trillion dollar bills on the sidewalk.

I've tried to make many of the same points here over the years, although with a particular focus on Austin:

• Wealthy cities are innovative cities.
• Density promotes innovation.
• Density increases productivity.
• Dense concentrations of people allow richer, deeper, more varied markets.
• Anti-density regulations pushed by NIMBYs drive up home prices in high-demand cities.
• Anti-density regulations pushed by NIMBYs are bad for the environment because they drive people from cities with mild climates to cities with hot climates, increasing average per capita energy use. 
• NIMBYism's root cause is homeowner risk aversion.

Ryan does not try to identify the one optimal density, or even claim that there is such a thing.  He doesn't argue that we all should live at New York or San Francisco densities.  Rather, he argues that cities benefit from rising density, whatever their baseline.  That's right. 

He's an eloquent writer who backs up his claims with academic studies.  I don't have any significant criticisms because I agree with him down the line.  I found a couple of nits to pick.  In the introduction, he states he has estimated that anti-density restrictions in the coastal markets have knocked 0.25 to 0.5% off GDP growth but didn't return to that point.  I would like to see more about this calculation.  Any discussion of rising demand for central cities should acknowledge the role of falling crime rates.  And he spends little space detailing the many ways cities restrict density.  Although it was not necessary to his argument, it would have been entertaining to read about some of San Francisco's more absurd regulations. 

The Gated City is a Kindle single but I understand it can be downloaded to your computer or phone even if you do not own a Kindle.  It is short.  It is half the price of a venti latte at Starbuck's.  Buy it.  Read it.

P.S.  When discussing density, Ryan usually used weighted density rather than standard density, and was kind enough to throw me a cite.