How do different types of voting systems lead to different types of party systems?
The kind of party system a country has depends a great deal on what kind of electoral rules (voting system) it has. I'll give you two examples to show how this works:
Here in the United States, we have what's called a "winner take all" and "single member district" system. That means that each particular election is for one seat only (one House seat, one Senate seat, etc) and whoever gets the most votes in the race wins while the others get nothing.
This leads to a two-party system because only parties supported by close to half of the electorate can get representation. If 30% of the people love your party, you have nothing. So a lot of little parties wouldn't make sense in our system.
In Germany, they have a very complicated system, but the major difference is that many seats in their parliament are picked via "proportional representation." In this system:
- each party lists all its candidates in order.
- Voters vote for a party and not for a person.
- The votes are counted and they determine what percent of the total each party got.
- Then the seats in parliament are divided up based on that -- if my party gets 10% of the vote, the top 10% of my candidate list get into parliament.
The limit on this is that a party has to get 3% of the vote to get representation in parliament.
So in Germany you get way more parties than we do because you can get people in parliament even if you only win 3% of the vote.
Sorry for the long explanation -- hope it helps.