Both self-organized wholes from people's behavior. A lot of it economic behaviour but also political. In turn, they organize people's lives.
Markets create cities, of course. Traditional market-towns. Trading city-states.
Cities can create markets too. Brasilia, willed into existence by a military dictatorship (BrazilianMilitaryCoup), is now also a market. Still maintained by government who is largest employer and sector of the economy here. And market may not be particularly good. But it exists, and strengthening as Brasilia diversifies into other economic activity. Many constraints on it though.
Pattern based approach might suite both. Urban patterns and market patterns. Can be both good (self-creating, freeing the people) and AntiPatterns (self-destroying, unable to contain the forces which leak out and destroy surroundings)
Of course, we think of cities as having to handle another class of constraints : spatial constraints ( SpaceVsInformationFlows)
But markets have external constraints too MarketsAreEmbedded
BlogosphereAsACity discusses similarities between an apparently non-spatial system : the BlogoSphere, and a city. So some issues may be similar for another non-spatial system : the market
See also :
- When they go wild : OnFavelas / ThePlanetOfSlums