How Supply and Demand Lists Are Determined

[samson]

Using the patched version of Civ2 that fixes the Dye/Copper bug, I was finally able to determine the correct demand formulas for Dye and Copper. Here they are:


Copper

Demand = Rivers + Roads
Techs: Electricity: 3/2 Computers: 1/4
CitySize: 1-2: Demand = 0 3-4: 1/2 5-7: 1x 8-12: 2x 13-17: 3x
18-22: 4x ... etc.
City Improvements: Marketplace: x 3/2 Bank: x 3/2


Dye

Demand = SupplyQuotientOfCloth + Roads
Techs: Chemistry: 1/2 Mass Production: 1/2



The factor they have in common (and which no other commodities use) is a dependency on the number of squares within the city perimeter which have Roads (or Railroad) terrain improvements. This must be the source of the D/C bug.

It's also interesting to note that the demand for Dye is directly dependent on the supply quotient of Cloth for that city. This is only relationship of its kind between commodities discovered so far.



samson

[Elephant]

The Dye-Cloth relationship makes you want to smack your head "duhhh...". I was expecting it to have something to do with coastal tiles, as most purple dye in the Mediterranean region came from shellfish. Oh well.

So why is copper demand influenced by rivers?

[samson]

It is what it is.
Perhaps the thinking was that the demand for copper (a coin metal) increased more in areas where trade blossomed.

[Elephant]

By that reasoning, Silver and Gold should have even more powerful Trade influences.

Now those of us who have adjusted to the bug need to decide whether to patch and relearn our bad habits!

[Elephant]

Andu Indorin over at CFC believes the Manhattan Project increases the demand for Uranium. Samson, did you test for Wonders influencing each of the S/D formulas?

[duke o' york]

How about city style influencing supply and demand?

I know that these depend upon the techs possessed, so that when your city style changes to Industrial, oil and coal become more popular, and when it changes to Modern you start to get Uranium demanded.

Just a thought.....

[solo]

Duke,

City styles are another thing triggered by tech discoveries, which also account for some supply and demand changes.

Samson did test wonders and found that the demand for Uranium doubles after SDI is built. (I assume he also tested the Mahattan Project and concluded it had no effect.)

Once the demand for Uranium is enabled by Nuclear Fission, this demand is based on the number of techs squared, usually resulting in a huge number. As commodity trades and city cycle updates occur, Uranium is almost sure to appear on every city's demand list. Any help from the SDI wonder is probably just overkill.

[Elephant]

SDI is a city improvement, not a wonder, but I get your drift. Another one of those "feels like it" myths.

[rah]

I just want to say thanks for all those that have contributed to this thread. When we play MP, we move a bit quick to get real anal about this, but some of the simple things have actually made of difference. It has influenced some city placements, and pop size related issues. Nothing better than delaying a delivery to your trade city a turn, having a good clue that the commodity will be demanded the next turn when it's currently not. It's an extra edge.

Thanks again.

[solo]

Elephant,

I was thinking of SETI, a dumb mistake, although in my defense I'll note that at least 2 letters do match (S and I)!

So it could be that Duke is right after all. Now that I think about it more, I do not recall if Samson tested for wonders or not, but suspect he did since his research was usually quite thorough.

[Elephant]

I think both Duke and Andu are commenting on things that are connected, like particular techs changing city "style", which is more noticable when playing than checking the S/D lists every turn. I vaguely remember something about Wonders, just can't find it in the threads right now. Wish I had that kind of time to do my own tests.

[LDiCesare]

(Shameless bump.) Thanks again to samson, solo and all those who spent time computing these formulas.

[Radyserb]

I have some problems with the formulae.

EXAMPLE in the attachement
Russian city Melbourne
on (142, 82) Map: 120x150

Values I calculated:
Wildcards: Gold/Gold

SQ/DQ:
Silver 102/64
Cloth 54/29
Gems 10/0
Spice -44/2
Salt -3/4
Hides 1/17
Beads -3/25,25
Wool 32/35
Wine -24/72
Silk 140/176
Coal 82/240
Gold Wildcard (6/72)
Copper/Dye (Bug)

Theoretically there should be Demand for Copper/Dye, Gold and Coal, and Supply for Silver, Cloth and Gems. Demand is right, but Supply is Silk, Cloth and Gems!!

Here the other values of the city and Civ:

Spoiler:

#of cities: 28?
Continent#: 23
ContinentSize: 19
Civ Technologies: 55+1
discovered: Pottery, Iron Working, Chemistry, Economics, Electricity and Combustion by another Civ
City Terrain:
Grassland: 14
Plains: 9
Hills: 1
Forest: 1
Ocean: 2
All Landsquares: 19
Special: yes
Roads: 10
City Improvements:
Just Cathedral by Michelangelos Chapel

Other calculated values (maybe are some wrong numbers???):

Spoiler:

# of Techs 56
DistanceToEquator 22
TemperateZoneOffset 8
LongitudeEast 67
LongitudeWest 0
DistanceToMeanMeridian 67
DistanceToPole 38
DistanceToDateline 8
PolarCircle 0

Help!