Overview

Voting Systems determine how votes are translated into seats. The same votes can produce wildly different results depending on the system used.

Core Idea

The core idea is representation. How do we best reflect the will of the people?

  • Majoritarian: Winner takes all. Creates stability.
  • Proportional: Everyone gets a slice. Creates fairness.

Formal Definition

  • First Past the Post (FPTP): The candidate with the most votes wins. (USA, UK). Leads to a two-party system (Duverger’s Law).
  • Proportional Representation (PR): Parties get seats based on % of vote. (Most of Europe). Leads to multi-party coalitions.
  • Ranked Choice (RCV): Voters rank candidates. If no one gets 50%, the bottom candidate is eliminated and votes redistributed.

Intuition

  • FPTP: Like a horse race. Only the winner matters. 49% of people can be unhappy.
  • PR: Like a pizza. If 10% want pepperoni, 10% of the pizza is pepperoni.

Examples

  • Gerrymandering: Redrawing district lines to favor one party. A huge problem in FPTP systems.
  • Spoiler Effect: In FPTP, voting for a 3rd party (Green) can help the candidate you hate most (by splitting the vote). RCV fixes this.

Common Misconceptions

  • Misconception: The candidate with the most votes always wins.
    • Correction: Not in the US Electoral College (Trump 2016, Bush 2000).
  • Misconception: There is a perfect system.
    • Correction: Arrow’s Impossibility Theorem proves mathematically that no voting system is perfect (fair, transitive, and non-dictatorial).

Applications

  • Electoral Reform: Debates over changing the system (e.g., FairVote).
  • Oscars: Use a form of Ranked Choice Voting.

Criticism and Limitations

  • Complexity: PR and RCV can be confusing for voters.
  • Instability: PR can lead to weak coalition governments (like Italy or Israel).

Further Reading

  • Gaming the Vote by William Poundstone
  • Electoral Systems: A Comparative Introduction by David Farrell