District Costs

[Plumfairy]

I apologize if this has already been covered somewhere, but:

Do we know what causes districts to become more expensive? It's pretty clear that their costs *do* increase, but I can't figure out what triggers it:

* It doesn't seem tied to the era; all the costs stayed the same just now when I advanced from Classical to Medieval.

*It doesn't seem tied to the number of districts, either globally or locally.

Any thoughts/ideas?

 

[Browd]

Moderator Action: That question is discussed at length in another thread, so please post any responses in that thread. This thread is closed.