As I like to point out, urban economists and urban planners like to prescribe higher "density" -- which sounds like a good thing when we think about the benefits of agglomeration economies. But they presume that city-wide or metropolitan-wide densities are what count. An associated presumption is that low densities and suburbanization (and "sprawl") are a uniquely U.S. phenomenon because of our peculiar policies.
There are also perennial discussions of "urban revival" and "urban renaissance" in the U.S. With respect to these, we are beginning to get the 2010 census data and we shall see. Yesterday's news re Chicago signals continued central city decline. There are probably pockets of success within the city, so again we shall see. Again, the whole city-wide density discussion is much too broad.
What about international comparisons? The data are not simple. I am aware of two sites that help a little. Urban audit covers the EU cities. This UN site covers many others. Again, we are stuck with large spatial units. For those places for which we have city and surrounding area data (correction: city and metro area data) for at least two years, which one grew most? (The data for the two years must be from the same source; do not mix and match.)
I was so inspired by the dribs and drabs coming from the U.S. Census Bureau, that I looked at non-U.S. metro areas. I found readings for at least two dates for central city and their suburbs for seven prominent places abroad. For Berlin (1991-2004), Montreal (2001-2006), Toronto (2001-2006), and Stockholm (1999-2006), the suburbs grew fastest. For London (1991-2004), Brussels (2001-2007) and Amsterdam (2001-2007), the central city grew fastest.
What can we say? We need more cases. And we have to be careful about international reporting peculiarities. But suburbanization does happen way beyond the reach of U.S. policies.
We'll know more as the rest of the 2010 U.S. census data arrive.