Major cities in many countries have become progressively less dense

A reader yesterday linked to the recently-published United Nations World Cities ReportSceptical as I am of most UN things, out of curiosity I dipped into a few chapters of the report.

On doing so, I stumbled on this chart


In a quite striking way it makes the same point made in an early post on this blog: as countries become richer, the cities in those countries tend to become less densely populated.  Here was the chart from the earlier post showing data for London as far back as 1680 (just over a decade after the Great Fire).


These numbers shouldn’t really be a surprise.  Space is a normal good –  people typically want more of it, all else equal, when they can afford it –  and technological advances make longer distance commutes feasible.

No doubt there will be some issues with how the data are compiled/estimated –  quite where are the boundaries around the “built up area”, and how well is that known for, say, 1855.  But the general proposition shouldn’t be surprising: it is easy enough to think of the cramped tenement dwellings of New York in the late 19th century.

Of course, these trends aren’t ones that seem to please either the United Nations or many of our own local councils.  This text is from the UN report, just after the chart above

In recent years, UN-Habitat has brought into the forefront of attention the need for orderly expansion and densification so as to achieve more compact, integrated and connected cities. UN-Habitat’s support for planned city extensions programmes as well as promotion of tools such as land readjustment aims to increase densities (both residential and economic) with compact communities in addition to guiding new redevelopment to areas better suited for urbanization. These interventions are suggested to be an integral part of the New Urban Agenda as elaborated in Chapter 10.

And the constant refrain locally is for “more density”, when there is little or no evidence that such densification is what residents would prefer for themselves.  Indeed, it would be surprising if the revealed preferences across time and across countries/cultures had suddenly reversed.

I have no particular problem if people wish to live in high-rise apartments, or in small townhouses with no garden.  And people will choose to do so if regulatory constraints limit their options –  eg if land simply becomes too expensive –  but it doesn’t look like a first-best unconstrained preferred choice for most people.  We don’t, for example, see such bunching in our own provincial cities –  where housing is less unaffordable than in, say, Auckland –  and of course by international standards even our own largest city, Auckland, is not much more than a large provincial city (just a bit smaller than, say, Nashville).

Freeing up the use of land around cities remains the key to making housing affordable again and providing the choices/options that people value.  Experience suggests more populous cities will cover more space.  That isn’t something officials and politicians should be trying to stop.