Two-speed urbanisation : shrinking cities amid urban congestion

Not all cities are expanding uncontrollably. Many are shrinking - equally uncontrollably it seems. They, too, need attention, says Tong Wu. What makes a city shrink? Today, the majority of the world’s population resides in cities, intensifying our concerns for the teeming metropolis, its worsening traffic snarls, soaring housing costs and growing unemployment. Are our cities too big? Are the consequences of urban environment degradation too great? What can be done to contain the growth of these ever-larger metropolises? These and related questions dominate popular debates and research. While many researchers are preoccupied with how to limit city growth, others argue for “making room for … cities” because, to them, it seems that attempts to limit urbanisation are futile; the appropriate response is to direct the growth, not to frustrate it1. With these headlines and debates, one would be forgiven for thinking that all cities in the world are growing rapidly and their growth is out of control. The reality is quite the opposite.