When we went round and round about markets in Oly I, someone (Greg?
Carl? ...?) suggested a Merchant of Venus-like approach to spice up
markets. Ed's comment above is very similar to this.
Create a set of demands for the world, such as "Newleaf demands 12
linen at 60" (giving a 20% bonus over the usual price of 50).
Randomly select a subset of them to be active at any given time. If
the set of active demands is smaller in size than the number of cities
in Olympia, then some cities will have demands while others don't. A
demand remains active until someone satisfies it by selling that trade
good. At that time, the demand is returned to the inactive pool and a
new demand is selected (possibly the same one again).
Of course, with a computer it's easy to generate the demands on the
fly, rather than having a preset pool. An adaptation of this model
might be to select a portion of the cities (say, 50%) to have demands,
and limit a city to one active demand at a time. When a demand is
met, return the city to the inactive demand pool, and pick a new city,
then create a demand for one of the goods that city trades (which I
think just means install another BUY order at a slightly higher
I suppose you could also do the same thing with gluts.