Urban economists have developed (and elaborated) models that show cities are self-organizing spatial units. This was a significant accomplishment. But most of the models are static. Is there evidence of self-organization as cities grow? What do we know?
Joyce Dargay, Dermot Gately and Martin Sommer have shown that when people join the middle class, practically anywhere, they want a car. This is pretty obvious, but their arguement from data is powerful. Wendell Cox shows that large cities practically anywhere grow outward.
The two findings fit together and they are ubiquitous. Does this suggest spatial self-organization over time too?
The sure thing is that there are strong policy differences (towards cities directly or indirectly re gasoline and related taxes) among the places in both studies. But these differences appear not to make a difference. Call it spatial self-organization.