Boris Gudenuf
Deity
The test of whether a Resource is needed in the game is whether it is, or represents, a Limiting Factor in obtaining or doing something. Silicon is not the Limiting Factor in manufacturing solid-state electronics, personal electronic devices, or 'smart' weapons. The limiting factor is the ability to refine the silicon to a degree of purity that couldn't even be measured a generation earlier: Very High Tech Manufacturing plants. The limiting Resource is Rare Earths, which, as you can expect from the title, are Rare but required.
However, this is a case where we can get the same effect without a new resource, by doing away with the artificial division of Resources into 'Bonus', 'Strategic', and 'Luxury' (or Amenity). The example I'll use, 'cause it's pertinent here, is Gold.
Gold was one of the first metals used, because it is easily separated from surrounding rock (it doesn't chemically combine with other minerals) BUT it is much too soft to be useful as a tool or weapon resource. It was from prehistory an 'Amenity' resource - people wanted to have objects made of it. Later, it (and Silver) was one of the basic Resources for making Coins, and so becomes a Requirement Resource for Coinage/Money and to facilitate Trade.
Still later (and coming to my Point), Gold is the preferred material for making electrical contacts in modern electronics, and so can be the Limiting Factor, or Resource, for the modern Amenity of Personal Electronics, a requirement for the control devices in your Science-Winning Spaceship, or modern weapons like Stealth aircraft, Cruise Missiles, and Modern Armor (which is crammed full of electronics in the form of Gun Computers, Laser range finders, fire suppression systems, etc.)
If you can get the Required Effect without adding 'extras' to the game, why not? Make Resources have multiple uses based on your Technology level (and Technological Requirements) and you can keep the same Resources useful throughout the game, instead of making some of them ('Strategic' horses and iron, for instance) become Obsolete during the last 1/3 to 1/4 of the game.
A Major Victory Condition missing from the game, but a messy one to implement. If Economics has been called "The Dismal Science", then initiating a Banking/Economic/Trade Victory might result in a Dismal Victory. Read John Gordon's "Empire of Wealth" (economic history of the United States, but unlike most economic writing, actually readable) - Economics/Trade is almost always NOT a straight upward line of Positives: it goes up and down, with Panics, Recessions, Depressions, Bank Failures, Money Supply fluctuations, and even within the same country, huge differences in the kind of Bank/Trade/Economic policies that people want.
The Tulip example is by no means unique: massive Wealth generated out of Nothing, then taken away in the blink of an eye (specifically, it all happened within a single Civ Turn!). I can't see anyone wanting to play a game in which changes in your Gold happen so fast that there is nothing the player can do about it!
On the other hand, the massive wealth generated or made available to Civilizations by the development of Banking, Stock Markets, Corporations, and other modern and semi-modern economic 'technologies' s not well-modeled in the game now, and could use some major revisions which could lead to a form of Economic Victory. It's just going to be a lot harder than adding a new Resource to the game.
