Wealth

§ Time and again, history shows us the importance of managing wealth properly. In the 16th century, Spain had access to the nearly limitless gold and silver of Central and South America, yet so much of this wealth was lost through corruption and mismanagement that Spain was unable to finance the ships and soldiers to protect her American possessions, leaving them vulnerable to attack by enemy nations and pirates. At the end of the First World War, Germany was bankrupt and shorn of her overseas colonies; yet in twenty years she acquired enough wealth to build and support the mightiest military machine yet seen in the world.
§ Wealth is an extremely important part of Civilization IV; manage your wealth properly and your civilization will flourish and thrive; squander it and your civilization will languish.
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Current Wealth

§ The "wealth counter" on the main screen displays your current wealth. This is usually a positive number or zero (if it is not, your civilization is in serious trouble!). The number adjacent to the wealth counter shows how much wealth your civilization is currently gaining (or losing) each turn.
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Commerce and Wealth

§ The amount of wealth that your cities are producing is determined by what percentage of your commerce is going into Research (and, later on, Culture). The percentage of your commerce that is turned into wealth is whatever is not being spent on research and culture. For example, if you are spending 70% on science and 10% on culture, the remaining 20% of your commerce is going towards generating wealth.
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Acquiring Wealth

§ City Wealth: Each of your cities generates commerce from working the spaces within its City Radius, and certain Resources such as gold, silver, and incense are particularly valuable. Constructing Improvements such as cottages and mines can dramatically increase the commerce of your cities - which will translate into more wealth.
§ Tribal Villages: When one of your units enters a "tribal village," the villagers might give you gold as tribute.
§ Capturing Cities and Plundering Improvements: You may gain an influx of gold when you capture an enemy or barbarian city. You may get a (far smaller) portion of gold when your units Pillage enemy/barbarian improvements.
§ Great Merchants: If your cities generate a Great Merchant, you can send him on a Trade Mission to a foreign city. This will generate an enormous amount of gold that gets placed in your civilization's treasury.
§ Diplomacy: You can acquire wealth through Diplomacy through the buying and selling of technologies and the trading of resources.
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Expending Wealth

§ City Maintenance: It costs a certain amount each turn to maintain your cities. This cost increases as the size and number of your cities increase. A city's distance from the Palace also affects its maintenance cost.
§ Civic Upkeep: Most Civics have upkeep costs associated with them that cost a certain amount of gold each turn. Some civics are much more expensive than others, so keep this in mind when selecting civics.
§ Inflation: As a game of Civilization IV progresses, your empire will slowly become more expensive to maintain due to the economic process known as Inflation. This will cost your civilization a certain amount of gold each turn in addition to all other costs. You cannot fight Inflation, other than by generating more wealth to counteract its effects.
§ Technological Research: You spend money each turn to finance your civilization's Technological Research; at some point, it will almost certainly be necessary to scale back research to prevent your civilization from going bankrupt.
§ Unit Support: Depending upon your current civics, you may be required to pay "support costs" for each Unit you have in play.
§ Unit Upgrades: After you have built a unit, future Technological Advances may allow you to upgrade that unit (say, from an archer to a crossbowman). You must pay for such upgrades.
§ Hurrying Construction: The Universal Suffrage civic allows you to spend gold to "hurry" a city's construction of units or buildings.
§ Diplomacy: You can expend wealth to grease the wheels of Diplomacy in many different ways. Enemy civilizations will usually agree to do what you want - if the price is right.
§ You can see a display of all of your civilization's current expenditures by opening up the Financial Advisor screen with the F3 key.
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Civics and Wealth

§ Your civilization's Civics greatly affect the rate at which you acquire/expend wealth. For example, some civics reward you for peaceful trading, while others cut down the cost of maintaining a huge army.
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Running Out of Money

§ If your civilization cannot afford to pay its current expenses, your cities will go on "strike;" they will cease production of units and buildings until your finances are in better shape. Further, you may lose units and buildings that you cannot afford to pay support for. When your cities go on strike, it is extremely important to get expenses in line with income as soon as possible.
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Early Wealth Mismanagement

§ It is quite possible to get yourself into serious financial difficulties in the early game. This usually occurs because you have built too many cities or units without first constructing the buildings and improvements necessary for your existing cities to support the costs of this expansion. The result is that your expenses greatly outstrip your income and your treasury goes away fast. There are a number of possible steps you can take to get out of this fiscal mess:
§ Tribal Villages: If there are any tribal villages about, send a unit to them; they may give you wealth as tribute. (This is a stop-gap solution at best!)
§ Lower Your Research Budget: Decrease the amount you are spending each turn on Technological Research using the button in the top-left corner of the screen.
§ Build Improvements: Build Cottages and other Improvements that exploit money-making resources within your Borders: mines for gold and silver, camps for fur and ivory, and so forth. Build roads to connect your cities to these resources.
§  Construct Buildings: Build Courthouses to reduce your city maintenance costs and Markets to increase your income. If you aren't able to construct those buildings yet, direct your Research towards the techs which will allow their construction. Failing to construct these buildings soon enough is a problem that nearly every newcomer to Civilization IV encounters!
§ Build Wealth: If your tech level allows, you can assign your cities to build Wealth rather than new units or buildings.
§ Emphasize Wealth: Set your cities to "Emphasize Wealth" when working the land around them. Be aware, however, that the city governor may not make the same choices that you would.
§ Adjust Civics: Check the Civics screen to see if you can reduce your "civic upkeep" by switching to less expensive civics.
§ Destroy Units: Delete extra military units. Destroy settlers rather then creating more cities that you cannot support.
§ Diplomacy: Depending upon your present technology level, you may be able to get gold from your neighbors - through trade OR coercion.
§ Capture Enemy Cities: You usually get some significant cash from capturing enemy cities or pillaging improvements.
§ Abandon Cities: If nothing else works, you can abandon money-losing cities. You can give them to other civilizations via diplomacy, or you can simply remove all military units from a city and hope that a barbarian captures it. (If things are THIS bad, however, you might also want to consider the "Start a New Game" ploy.)
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