Trade??

[Mercatia]

Ok I've been trying to figure out if there is a benefit to trading between cities that offer something that the caravan's originating city demands. Also if it does what is the benefit?

[Scouse Gits]

Trade is a vast topic in the game and there are still some aspects of the subject that are not fully understood.

The trade arrow represents the wealth of you empire…science/gold/luxuries…and the tax rate sliders allow you to apportion the riches of the economy in any direction you choose, subject to the limitations of your government.

The delivery of a demanded commodity from city A to B has the following advantages:
1) A one off gold/science bonus…if Hides from Antium to Rome pays 50g you will receive an equivalent science bonus of 50 beakers towards your next research target.
2) You will receive an ongoing trade increase in both cities. The arrows towards the bottom of the city screens represent this bonus. In the early stages of the game these will be typically modest numbers…1 to 3. However, as the cities grow the numbers increase. Incidentally, that is one reason in the Mad Succession Game, I was so keen to grow the capital.

Below is a discussion on trade between samson/Dave V/Adam Smith that took place about a year ago. This gives an insight into the finer points of the subject.

__________________________________________________ __________________________

Trade route basics.

The formula for the number of arrows a trade route provides is:

TradeFromRoute = ( (SourceTrade + DestinationTrade + 4 ) / 8 ) x Modifiers

where SourceTrade and DestinationTrade are the two cities' worker-generated arrows (WGA) minus corruption. Existing trade routes in neither city affect the amount of trade generated by the new route. Trade route modifiers are:

Road: +50%

Railroad: +50% cummulative with Road for 100% total.

Airport: +50% Both cities must have an airport. If either a road or railroad bonus exists, airports have no effect.

Superhighways: +50% in the city with the SH improvement only. Note that the SH also increases the worker-generated arrows, so its influence on trade routes is twofold.

Same Civ: -50% If both cities belong to the same civ, the trade route is halved. Thus, a railroad bonus between two cities of the same civ is equivalent to a non-bonus route between cities of different civs.

Distance between cities has NO effect on trade route calculations. Being on different continents has NO effect. Commodity type and Demand status have NO effect. Technological discoveries have NO direct effect on trade route calculations. All of these things affect delivery bonuses only.

Trade routes are dynamic. If you shift workers, substantially reducing or increasing the number of arrows they generate, the trade routes change. It takes 8 worker-generated arrows to increase a trade route by 1 arrow. If the railroad bonus is in effect, 8 WGAs will increase each route by 2 arrows. If you have Superhighways in addition to the railroad bonus, increasing WGAs by 8 will bump the trade routes by 2 or 3 arrows on alternating increases in WGA arrows. Road and railroad bonuses can be lost temporarily if the road/rail connection between cities is interdicted by a non-allied foreign unit. When the foreign unit is removed, the bonus is restored.

As for your original question, Rufus, yes, there is a way to replace an existing low-paying route. Generally speaking, higher paying routes replace lower paying ones with the road and rail bonuses being factored in. However, it appears that the same-civ penalty is not considered when a replacement route is compared to an existing one. This is unfortunate as it means that high paying foreign routes can be displaced by mediocre domestic ones. The foreign city must be able to beat out the domestic one in the amount of the arrows it contributes to the route calculation.

The trick to doing this is to remove all workers from trade producing squares in the domestic city whose route in your source city you want to replace just prior to delivering the new freight to the foreign city. This will reduce the value of the existing trade route to its minimum. If the domestic city is benefiting from a road/rail bonus, you may even want to cut that connection for a turn by pillaging your own rail.

Also remember that multiple routes into the same city require different commodities. If you send Copper to a foreign city which already has a "(Copper)" route established with your source city, it won't create a new route.

Hope this helps,

samson

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Samson - a very well written and comprehensive explanation. One minor quibble - when running lots of caravans into my capital, I've had (for example) 6-arrow routes replaced by 4-arrow routes. So I think the road/rail bonus may not be factored in (or maybe it is checked in the originating rather than the destination city).

DaveV,

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Thanks.

What you are describing is the problem - the loss of higher paying routes to lower paying ones. This is often caused by inbound freight. The remedy requires an outbound freight. Road/rail bonuses do seem to be checked correctly on outbound freight. I've had freights to foreign cities not replace domestic routes w/o a road bonus, but when the road bonus is in effect (all other factors the same) the foreign route does replace it.

However, on inbound freights it may be that none of the bonuses are checked as to how they affect the destination city. In any event, the solution is the same: reduce the trade arrows of the source city (temporarily) to prevent it from replacing an existing route. Unfortunately this will also reduce the delivery bonus. But in the case of small source cities delivering freights to an SSC the loss shouldn't be too much.
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Below by Adam Smith:

Bonuses for Fulfilling Demand, By Commody
Here are the bonuses for fulfilling demand at a destination city. The bonuses are expressed as a multiple of the bonus for fulfilling a demand for hides. For example, if a route from A to B demanding hides resulted in a bonus of 100, a route from A to B at the same time demanding beads would result in a bonus of 200.

I determined the multiples by creating a caravan in the Cheat menu (v 2.42), completing a route to a given city, reloading, and then completing another route to the same city using a different commodity. These multiples apply to the one-time bonus for completing a route, not to the continuing income from trade. While the values of the commodities are generally in the order listed in the Supply and Demand window, there are several exceptions such as coal and cloth.

1x: Hides, Salt

2x: Beads, Copper, Dye, Wool

2.5x: Cloth, Coal, Silver, Wine

3x: Gems, Gold, Silk, Spice

3.5x: Oil

4x: Uranium

__________________________________________________ ________

Complied by SG(2) with thanks to samson, Dave V and Adam Smith

[Straybow]

No, I think she's seen the Trade issue discussed recently. I think she means the other way around. If ScouseHolme demands Coal, Copper, Spice and sends out a Wool caravan, Aleppo demands Wool and supplies Copper. Does the supply of Copper have any effect?

When a foreign Caravan/Freight arrives in one of your cities it "steals" one of your supplied goods, if you have an unused one. OOOooo, I hate that. Anyway, you see the route as though you established it using that supply but you get nothing for it.

Maybe it takes originating city demand into account if there is a choice. I haven't figured out how it chooses, since I always have routes by the time any foreigner arrives. Many times I can't see the originating city to know what is demanded.

The other way around, we have no idea what the foreign city supplies. Cheating could tell, but I don't think it is factored into the bonus. It appears to be a straightforward multiple based on supplied commodity.

[Scouse Gits]

I have long been convinced (without I must admit a shred of solid evidence) that the existance of a potential 'return route' enhances the one off bonus - much of my trading is hamlet to SSC internal stuff and the odd 'rogue' bonus has caused me to think this way...

SG[1]

[Straybow]

Could be that samson, Dave, Adam, Xin, et al. just never checked. Someone started a thread about a more careful analysis of the factors, concluding that

Base bonus = ((distancex+10)x(source trade+destination trade))/24 is inaccurate, and

Base bonus = (2x(distancex+10)x(source trade+destination trade)+1)/48 is more accurate.

Maybe there are return bonuses, too; if so they must be rather small in comparison or the above researchers would have discovered them.

[Mercatia]

Hmmm ok Ive been checking Samson, Dave V, and Adam's Smiths
theory. The thing is part of this theory is disputed in the manual I got with MPG edition (although the disk was stolen). I am assuming that MPG is similar to the 2.42 I own now.

Quoting from the manual page 91.
If you capture a rival city with whom you were previously trading, the trade route remains active. However the amount of trade it generates is reduced, because items which were once exotic imports have become domestic commodities.

So the theory that the distance and rival nation trade route only effect the bonus I think maybe a mistake????

Also Straybow after espionage is discovered I try to keep a militia of spys to investigate foriegn cities. This gives you exactly what they produce just as it would if they were your own city screens.

However I think in 2.42 Im having more problems because the trade routes seem to randomly stop. Maybe they run out of a commodity and switch to another commodity thereby stoping the original commodities route?

Ok now I've given myself a headache.

[Scouse Gits]

Told you some aspects of trade are not understood.

I would also assume that the trading patterns are similar between 2.42 and MPG.

As soon as you capture an enemy city the trade routes from your cities do decrease as they are counted as internal trading.

City commodities on the supply and demand side change with their growth...sometimes! However, this does not explain repeated supply/demand for a product between any two cities. A couple of years ago I had a huge capital that kept producing silk...the very same item was demanded by a fat AI city on another continent. This went on for centuries and was worth rush buying the silk freight each turn for the vast profit in gold/science.

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SG(2)

[Scouse Gits]

As a rule of thumb, when a conflict exists between the manual and considered statements on these boards - trust Apolyton -- the manual has proved to be totally incorrect so often - in fairness so have individual Aplytoners, but rarely a sizeable consensus

SG[1]

[Mercatia]

I know manuals aren't always correct. But there has to be something to this a little because I sent a caravan into a city right before I took it from AI the trade rate went from 3g to 1g per turn after It was my city.

[La Fayette]

Mercatia
When you send a caravan to another city you get a one-time bonus in gold + the same amount in beakers (I won't discuss that now).
You also get a trade route (trade arrows written in your city screen). Mind you! If the destination city is also yours, you get 2 trade routes, 1 in the origin city + 1 in the destination city, but the value of each of those 2 trade routes is 1/2 of the value of 1 equivalent 'foreign' trade route (so the overall value of the trade routes you get is the same, but foreign trade makes you 'give' a trade route to the foreign city you are trading with.
To make it short, long distance foreign trade of high value demanded commodities is much better if you consider the one-time bonus, but it is no better if you consider the continuing trade route (this is the cornerstone of my 'twin cities' strategy).

Straybow
IIRC 'someone' is William Keenan who discussed that topic a lot with debeest

[Thoddy]

Originally posted by Scouse Gits
Trade route basics.

Trade route modifiers are:

Road: +50%

Railroad: +50% cummulative with Road for 100% total.

These bonuses are not correct
correct its only 33 1/3%( road) and 66 2/3 % (RR).
Roads(RR) must be at the optimal path.

the bonuses are lost, if the distance between the trading cities exceeds 22 or 23 tiles.

[Scouse Gits]

Thoddy - I am only quoting what I believe is the established wisdom in this area. What is the source of your figures?

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SG(2)

[Straybow]

Proof in the pudding

Thoddy, look at the Mad 2.42 game in the Civ2 General forum. ScouseHolme has Colossus etc and 73 WGA. That alone is worth 9, or 10 if the originating city has 7 WGA. At the start of my go as leader only one city (Erie or Unitysomething) had road & rail connection, its routes to SH were worth +10 or +11. No other city had any valid trade connection.

The city right beside (I renamed it Sarzanagrad) got only +5 (11, -50% same civ penalty, rounded down). That becomes the base value of the route. When the proper road connection was established Sarz got +8 (+50% over the unrounded same civ base). With the rail completed each route got +11 (+100% of unrounded for rd & rl).

Road connection +33% doesn't work with these numbers, that would only get at best +7.

[Messer Niccolò]

Re: Proof in the pudding

Originally posted by Straybow
The city right beside (I renamed it Sarzanagrad)

... and Politburo will send you to chop some woods in the northern parts of the country for this... we won't forget!

[Thoddy]

http://apolyton.net/forums/showthread.php?s=&threadid=2483&perpage=25&pagenumber=3

See also the link to the german civ2 Forum.

See my post from 23.11.2001.
I will verify this, but this will last 1 week or so, because of time.