How many parties matter?
Legal party count can be much larger than the number capable of winning seats, joining coalitions, or shaping government.
← AFDES Civic AcademyComparative Democracy · Coalition Lab
Party Systems
Democracy can organize competition around two large parties, several significant parties, one dominant party, or shifting coalitions. Build a majority and see why party-system structure matters.
Build a coalition ↓Coalition Builder
Winning seats and governing are not always the same thing.
Select parties to assemble a governing majority in this hypothetical 100-seat legislature.
Selected coalition0 / 100 seats
51
No governing majority yet.
Select one or more parties. A simple majority in this model begins at 51 seats.
Effective number of parties3.63Based on seat shares in this teaching scenario.
Teaching model: Coalition formation depends on ideology, institutions, confidence rules, presidential powers, party discipline, and bargaining—not seats alone. The “effective number of parties” is a common concentration measure, not a rating of democratic quality.
Party-System Lens
Count parties, but also ask how competition is structured.
Can power alternate?
A dominant-party system is not defined merely by repeated victories; the fairness and openness of competition also matter.
How are governments formed?
Electoral rules and constitutional design can reward single-party majorities or make coalition bargaining routine.
Sources & Further Reading