The Spatial Organization of Cities: Deliberate Outcome or Unforeseen Consequence?

The raison d’être of large cities is the increasing return to scale inherent to large labor
markets. The cities’ economic efficiency requires, therefore, avoiding any spatial
fragmentation of labor markets. In simpler terms, it means that all the locations where
jobs are offered should, potentially, be physically accessible from the place of
residence of all households within about an hour travel time. This requirement should
be borne in mind when evaluating alternative urban shapes. Any type of spatial
organization implying that residence and jobs should be matched individually – i.e.
that workers need to have a good access only to their current job – contradicts our
premises that large competitive labor markets are efficient and that efficiency alone
justifies the complexity and high operating costs of large cities.