(Apologies in advance if this is a replication of a known report... I'm a bit of a lurker but have never posted here before.)

I've found a bit of a pattern in the population count issues that come up in the current beta build.  I think population use at cities is getting counted multiple times, depending on how many cities are actually using population or have used population in the past...

Anyway, here was my test.  Started a game, built three cities - Alpha, Beta and Gamma (in that order).  Beta and Gamma each just have huts (0), Alpha has two huts (0), a Workshop (1), an Inn (10) and is building a Merchant (10).  I've also got a pioneer (1) built, for a total population use of 22.  So far so good - everything seems ok.

Step 1 - build an arcane lab at Gamma.  Immediately, population use increases to 48.  Killing the queued lab drops this back down to 43 - twice Alpha's population usage, plus the one for the pioneer.  Queueing other things at Alpha now costs twice what it should (10 usage for an arcane lab, which is fully recovered when it's removed from the queue).  Killing buildings at Alpha at this point also recover twice what they should... and you can reduce population usage down to 1 (for the pioneer) by destroying all of the buildings that use population.  Even if you do this, costs are still double at Alpha and single at Gamma.

Step 2 - Having killed the lab at Gamma (pop use = 43), now build an arcane lab at Beta.  Usage jumps to 74.  Population costs at Alpha are now triple (21 x 3), and costs at Beta are now double (5 x 2).  Costs at Gamma (third city on the ledger list) are still normal (0).  And the pioneer still seems to be only 1.

Step 3 - build a 4th city (Delta).  No issues when building the city, no issues when building huts.  (Costs at Alpha are still triple at this point.)  However, the first build of a structure that uses population now causes Alpha to be 4x, Beta to be 3x and Gamma to be 2x population use.

I've replicated this from game to game (at least early in games).  Doesn't seem to matter at what order you start building things or what is built (labs, workshops, monasteries...).  It doesn't seem to matter if you kill off all of the buildings in a city... once you build something that uses population, the multiples are applied, and they're applied in the order the cities show up on the ledger rather than alphabetically or anything like that.  Razing one of the cities will affect this, though... reducing the multiples for those cities higher on the list, if that makes sense.

[I know nothing about programming.  But maybe once cities use population they are put on some kind of list and counted multiple times from the top (Alpha, plus Alpha and Beta, plus Alpha and Beta and Gamma...?  The idea of directly applying a multiple makes no sense at all, but I can at least see the possibility of something like that...]

Haven't tested for building units or anything like that.  I was just happy to be able to predict how much population would be used for buildings.  I'd be happy to send a savegame file, but this pattern was consistent and replicable across all of the games I played, so it seemed a bit redundant.

Anyway, I hope that's helpful.

--Dan