The establishment of a Representation system, such as a Parliament or a Senate institution whose members are directly elected by the people, is a necessary step for preparing your empire for enlargement. It greatly increases the efficacy of newly-established local governments, which facilitates acquiring new Social Policies. The effect is such that your empire immediately enters a Golden Age.
- Each city you found will increase the Culture cost of policies by 33% less than normal.
- Starts a Golden Age.
This is a high-end policy which works best if adopted early in the game. The reduced Culture cost for Policies is not retroactive, though, so it makes sense to adopt Representation before greatly expanding your empire - this way you'll get the best out of it. This will help towards the gaining of Rationalism policies later in the game, and indirectly boost science (compare Landed Elite, which leads to science by population).
On the other hand, the benefit of a Golden Age is greater the more Gold production you get from terrain, so you must make sure you have enough luxury resources, preferably with the respective tile improvements.
Representation is a policy where the citizens of a nation appoint "representatives" to run the government. This might be considered a step up from collective rule, once the population becomes too large to support that government type. In a representative form of government, the country is divided into smaller, more manageable districts (or parishes, or states, or whatever), and each chooses one or more local citizens to represent their interests in the government for a set period of time. The representatives form a parliament or some other kind of deliberative body, and they rule the country. While most representative forms of governments are republics, it is not strictly necessary. Some representative governments elect temporary or permanent kings and other nobility to rule over them.