So in Civ5, citizens innovate at a fixed pace per citizen per turn.
You don't have a empire-wide "think more, earn less money" slider. In order to do that, you need to find a way to turn wealth (gold) into thinking.
Methods include research pacts with allies, building libraries (turning production and maintenance into science), specialists (turning city size, library room, and food into science), other buildings, social policies, etc.
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The game has multiple different economies, unlike Civ4 which basically had one.
In Civ4, given the slider, converting between gold, research, (global) culture and espionage was trivial. Everything else was on a nearly pure individual city level -- happiness, health, food, culture, etc.
In Civ5, happiness, culture, money and science are all hard to convert between. You have to manage each of them.
Each of them gives benefits if you produce "lots" of it. Some give penalties if you don't produce enough.
At the start of the game, the ways to convert one to another are limited -- by mid game, they are more common, and it continues to ramp up (1/2 of excess happiness produces culture is an example of a mid-game converter of one economy to another).
Individual cities have production, culture, food and great person economies.
Territory in Civ4 was a purely local thing -- in Civ5, it is a mixture of efficient local (local culture) and inefficient global (global cash).
It remains to be determined if the economy is balanced. Does cash-rich dominate? Food-rich? Production-rich? Specialist economies?
Cash-rich economies can rush build things and generate extremely focused empires (you cash-rush a science city or two, you cash-rush units in a military-specialist city, you build 1 or 2 production-heavy wonder cities and a handful of military workhorse cities).