Trade Routes

[debeest]

Hey! I was just about to post my observation that the widely accepted formula for trade payoffs was wrong, and here's somebody already working on the problem. Is this the best website in the world, or what? Thanks, Mr. Keenan! Keep us informed.

[Campo]

quote: Originally posted by William Keenan on 07-10-2000 10:38 PM Cargo Modifier x100% Any cargo not in demand

So any undemanded cargo is equivalent? Does that apply to initial bonus only, or to ongoing trade benefits?

My impression (not based on any facts) was that the more prestigious cargos gave greater benefits, even if not demanded.

[tonic]

I have done a quick run for the one-off trade bonus with freight commodity demanded as variable and have come up with the following results. It appears there are 4 broad groups. So Campo may not be that far off:

Factor of 1:
Hides, Dye, Copper...

Factor of 1.25:
Cloth, Wine, Coal, Silver

Factor of 1.5:
Silk, Gold, Spice, Gems

Factor of 1.75: Oil

Factor of 2: Uranium

The results are independent of distance between the two cities and the amout of existing trade. I find the factors given by Lancaster a bit hard to follow. What the factors I use here imply is that if you get 100 gold bonus with Dye, you would get 125 gold with Wine, 150 gold with Gems and so on (all demanded). I note too that Coal is not in the Silver-Cloth-Wine group of Lancaster's.

Also to confirm that

1. For UNdemanded commodities there is no difference in both the bonus and the trade.

2. The trade generated by the established route seems independent of the commodity whether demanded or not.

3. The type of transport link (no roads, roads, or railroad) between the two cities has no effect on either bonus or trade ie the Lancaster formula is awry on this factor as well (This link factor had previous been pointed out in a thread in the archives).

[geofelt]

In a recent game, I was disappointed to lose colossus to the chinese. As it turned out, the city was on a nearby continent. I established a city on that continent, but did not capture the colossus city, instead, I sent caravans from most of my cities to that one location and got an incredible amount of bonuses and continuing trade.

[William Keenan]

Tonic, don't fall into the same pitfall that Robert Lancaster did in his research. That pit fall is to assume that a particular component (such as the cities being connected by roads) is not part of the formula just because in one particular test it made no difference to the outcome. The trade formula is allot more complex then it seems. There are conditions when things like the cities being connected by roads factor into the formula and other times when they do not. For example, when calculating the cash/science payoff 50% is added to the total if both cities are connected by roads but only if they do not both have airports.

Similarly, if a cash/science payoff exceeds 210 gold a different formula is used to calculate it's value then for payoffs below 210.

[tonic]

WK, although I used one scenario/game I did test the transport link hypothesis for at least three city-pairs with the same negative results. I'm a firm believer in the empirical approach and this is one which can be done given the time.

On the science bonus issue, it would be helpful to get some confirmation on what applies eg currently there seems to be two schools of thought about it in Fundy. One is represented by Xin Yu who assumes that you only get 50% of the gold equivalent and the other thinks it is 100%.

As I implied in my last post here, it certainly seems worthwhile to put out a more accurate version of the trade formula. Just on the one-off trade bonus, the factors given by Lancaster seem awry.

[Novi Nomad]

Has anyone else had a trade route disappear? I established a route in the early portion of a game, and was getting something like +3 trade arrows for it. When I was doing something in that city later in the game, the commidity was still used up, but the +3 trade arrows were no longer there...

[Tom DeMille]

Novi, Perhaps the city you were trading with was destroyed.

[Novi Nomad]

D'oh! Didn't think about that. I guess that might explain the disappearing arrows...

[Laertes]

From a Slow Learner:

What about poxy wool and cloth! I have usually suffered from a couple of cities that can produce these caravans, but that only have 2 small "customer" cities. To add insult to injury, they usually stop demanding wool by the time I turn up with my god forsaken caravan.

In my current game at deity, wool is a plague! I have at least 12-15 cities where wool is one of the available commodities, and I cannot find any takers!

Any tips?

Fergus

[SCG]

I'd send out the caravans anyway Just find a nice big city to send them to. The more trade routes per city, the better. And eventually the commodities will change to something you can get big trade from, and you have the extra trade in the mean time. The other thing I do is try and build a 'great road' between my civ and the AI I am most likely to trade with. It doesn't affect the size of the trade bonus (contrary to most of the posts here), but it gets your camels there a heck of a lot quicker. Also, that road can facilitate the building of more cities as well

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April Cantor: Sire, in order to expand further we must first gain favor of the King

SCG: darn, I've never really got the hang of that tribute thing, guess it will be a long time until i make prince

*goes off and starts gifting gold and techs*

[tonic]

quote: <font size=1>Originally posted by SCG on 07-26-2000 07:33 AM</font> The other thing I do is try and build a 'great road' between my civ and the AI I am most likely to trade with. It doesn't affect the size of the trade bonus (contrary to most of the posts here),...

Well in my earlier posts here I thought so too but spurred on by Xin Yu's contrary views I did some more tests with a different scenario and found that the original Lancaster formula holds in some cases ie

Roads increase the bonus by 50%
Railroad by 100%

The ongoing trade between the two cities is also increased proportionately.

At this stage (I am still running more tests) all I can say is that I can see no rule or pattern. The increase may apply to one city-pair, but not to others in the same scenario. Others may wish to do the tests as well, using different stages of civ development.
[This message has been edited by tonic (edited July 26, 2000).]

[SCG]

well, there certainly are some odd occurances with trade routes. The one I'm most puzzled about is under what conditions does the trade route itself roughly double. (ie instead of getting 8 trade arrows like every other city nearby, you get 16 arrows in city info). I used to think it had to do with proximity to the city you were trading with, but I've had too many examples to the contrary. And I'll try and see if there is any corrilation between the road/railroad bonus and the increased trade arrows.

Edit: I should point out that _all_ of my cities are connected by railroad, and I built a railroad to the doorstep of the capitol of a civ i reduced to 1 city. As a test, I took a saved game and pillaged first the railroad and then _all_ roads surrounding the city and there was no change in the cost in the same caravan in each reload. Also, I should add that a majority of the cities with doubled trade routes arrows are within 20 or so tiles of the trade city, but there are exceptions to that. And it doesn't seem to be related to which civ founded the city either.

------------------
April Cantor: Sire, in order to expand further we must first gain favor of the King

SCG: darn, I've never really got the hang of that tribute thing, guess it will be a long time until i make prince

*goes off and starts gifting gold and techs*
[This message has been edited by SCG (edited July 27, 2000).]

[Matthew]

Fergus:


Often as soon as you establish a trade route with that wool caravan another commodity will become availible. Even if it isn't immediate, it's likely that a commodity will change faster once it has been used up. I've even noticed that using a food caravan from a city to build a wonder can change commodities. So if you really hate wool, try using a caravan or 2 from that city to help build a wonder.

What really sucks is in the endgame, you are trying to get to AC ASAP, and you have 4 or 5 enourmous cities supplying oil, you gave every civ in the world the Automobile as soon as you got it, yet none of them ever demand oil, and all your cities are justtoo darn close to make self trade all that lucrative.

I try to build roads to facilitate trade also. They are generally made of Magellan boosted boats. It's nice to know that the commodity in demand in the forign city on a continent half way around the world will not change before your caravan gets there because it will get there on the same turn it is built.
[This message has been edited by Matthew (edited July 27, 2000).]

[William Keenan]

Matthew, your right to assume that a city's demand for oil is connected to the Automobile tech, but the tech by itself is not enough to create the demand. A city has to build super highways first.

BTW it is Industrialization that creates the oil supply.