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Technology

How Electoral System Design Influences Party Fragmentation

Quick fact

In proportional representation (PR) systems, the effective number of parties often reaches 4–6, while majoritarian systems like the UK or the US typically see an effective number of just 1.5–2.5—a direct result of the electoral rules.

Why this is interesting

Why do some elections produce two dominant parties, while others lead to a dozen small ones? The answer lies not in voters or issues, but in the simple rules that translate votes into seats.