Commerce Improvement Question

[drsparnum]

Does the commerce generated from towns increase the science of your nation, or the science of the city that is working that square (which in turn increases the science of your nation)?

For example, if I build a town that generates a few gold near a city does that gold go directly into my gold pool? Or does that gold first suffer deductions from city expenses and then the left over gold is converted to science.

I'm really wondering about trade improvements and research improvements. If a hypothetical building increases city income 50% is it also increasing science 50%, because the city will have more excess cash? If a library increases science 50%, does a library benefit from being built in a city surrounded by a lot of towns? If it is true that gold is produced locally at a city, and then expenses are deducted locally, are trade improvements +X% better than science improvements +X%?


Example:
City income with towns: 100
City expenses: 10
Extra revenue for science: 90

If a building improved income 50% then it would become:
City income with towns: 150 (100x1.5)
City expenses: 10
Extra revenue from science: 140 (150-10)

If a building only improved research 50% it would become:
City income from towns: 100
City expenses: 10
Extra revenue from science: 135 (100-10 then x 1.5)

[Enigma_Nova]

Commerce from Towns goes into your Commerce pool, which is then divvied up by your Science/Culture/Income slider.
Great Prophets have gold that goes directly into Income.
I know that Libraries and Banks are per-city.
Libraries work on Specialist-generated Beakers, and Commerce assigned to Beakers.
Banks work on Specialist-generated Coins, and Commerce assigned to Income.

This should clear matters up.

[Falconne]

Civ does it's gold/science work from common pools, so everything you earn from a city goes to that pool and city maintenance is deducted from that - so any building that increases gold output in a city does so without maintenance comming into the equation.

Although commerce and gold are represented by what seems like the same icon, they are two different things. Commerce is collected from worked tiles themselves (as the gold coins you see on tiles) and is then converted to science, culture and gold according to your global slider settings.

So say you have science set to 70% and culture to 10%. If your city earns 10 commerce, the city will output 7 beakers, 1 culture and 2 gold coins. It is to *this* output that most city improvements add to, not to the raw commerce output of the city.

So in the above case, you'll get good results from building science improvements in that city, but not much bonus from banks and such. If you reduce the science slider so that more commerce is turned into gold, then that situation reverses.

[drsparnum]

But you have to set that slider at a national level. So there isn't some way to trick it and let city 1 (that has a library) run a high science slider and city 2 (that has a bank) run a high commerce slider, is there?

[Proteus_MST]

Nope,
I first thought, as the sliders are also present within the city view,
that you could finetune everything per city,
but after I tried it I found out that changing the sliders within the city view just changes the sliders at a national level.

[GeoModder]

No, but city radii can be terraformed according to the most appropriate thing. some resources give good amounts of commerce, have alot of river tiles nearby so that one is good to make a banking/commerce center of in combination with towns, despite perhaps your tax slider being only 10% or so.

[Jamski]

Add merchant / scientist specialists as appropriate. Food really is god in Civ4.

[Enigma_Nova]

If food were god, we'd see more farms and less Cottage Cheese.

[gilfan]

Farms suck, towns rule. There's very little reason to have specialists except for 1 or 2 cities that are set up as great people factories.

Every farm with biology (+2 food) that you build to support one specialist is one fewer town you have. It's hard to justify giving up 1 hammer and 7 commerce to get a specialist, except for your GP cities.


Honestly, I wish farms didn't suck quite so badly. Another +1 food modifier for farms somewhere in the middle of the tech tree (near the banking tier) would be a good addition IMO

edit: Actually, if someone were to do this, I suppose it might as well be +1 food with civil service, in addition to spreading irrigation

[JackRudd]

The best use for farms is in accessing special resources (corn, rice and wheat). A city near those probably makes a good GP factory.

[Diadem]

Ok:

All worked tiles give their output to the city they belong to. So a town outputs its gold to the city that is working that tile. If no city is working the tile (for example you have 5 town around a size 4 city) the tile does not generate income. The same is true for mines or farms, or anything.

To the total commerce produced in all tiles a city is working, is added the income from trade routes. That is the raw commerce for that city. To this, modifiers are added. With bureaucracy your capital gets a 50% bonus, for example.

After this, your slider is applied. A globally set percentage of your commerce goes to science, a percentage to gold, and a percentage to culture. To these counts, the production of specialists and superspecialists, as well as some buildings (for culture), is added. If you build science/wealth/culture with your city that is added in this step. This gives you your raw beaker (science) or gold (income) count. To this, modifiers are applied. A library increases your total beaker output by 25%. This bonus goes over your science, not your commerce. So your income is unaffected. The same for all modifiers like this.

This is all on a per-city basis. Next step, everything from all your cities is thrown together. That gives you your nation's beaker production, which determines your techrate. It also gives you your total income. From your income expenses are deducted, also globally. An individual city can not go broke. A city can cost 20 gold a turn while it only produces beakers. No problem, as long as you have enoug gold to compensate in some way.

So the cost a city gives in no way affects its production.

[Urban Ranger]

Originally posted by gilfan
Farms suck, towns rule. There's very little reason to have specialists except for 1 or 2 cities that are set up as great people factories.

Priests are good, though, esp if you have certain civics.

[JackRudd]

And Wonders. Angkor Wat + Sistine Chapel + lots of priests is a nice combo.

[Enigma_Nova]

The Sistine Chapel has a use now?
I know Angkor Wat is powerful, but the +2 culture on Priests doesn't seem quite so important.

[JackRudd]

It's a useful addition if you're going to be focusing on specialists.

Combine it with the Statue Of Liberty and you've got yourself a nice pseudo-creative continent.