Lecture Notes: Voting Systems and the Median Voter Theorem
Key Topics
Median Voter Theorem
Multi-Candidate Elections
Condorcet Winner
Agenda Setting in Voting
Median Voter Theorem
Concept: In a two-solution legislative scenario, the solution favored by the median voter is expected to be adopted.
Impact: The median voter holds significant power as their vote can determine which legislation passes.
Condition: This theorem only applies effectively when there are two proposed solutions.
Multi-Candidate Elections
Scenario: When there are three candidates, the election outcome can differ significantly.
Example: Orange, Yellow, and Red Party candidates.
Voters choose candidates closest to their position.
Outcome: The candidate with the most votes wins, but median voter is not decisive here.
Example: Orange Party wins with about 46% of the vote.
Voter Dynamics: The winner can result in some voters feeling dissatisfied.
Condorcet Winner
Definition: A candidate who would win in every head-to-head matchup against other candidates.
Historical Context: Concept named after Nicholas de Condorcet, a French philosopher and mathematician.
Example: Red Party is the Condorcet winner—wins every head-to-head contest.
Voting System Suggestion: Use a system that selects the Condorcet winner when available.
Non-Condorcet Scenarios
Problem: Not all situations have a Condorcet winner.
Agenda Setting: When no Condorcet winner, agenda setters determine outcome.
Example: City council with 9 representatives and 3 proposals (A, B, C).
Votes can be manipulated based on the sequence of voting.
Result: The agenda setter (e.g., chairperson) can decide the enacted policy.
Importance of Agenda Setting
Influence: The agenda setter, such as the Speaker of the House, holds substantial power in determining legislative outcomes.
Media's Role: In elections, the media can influence public opinion by focusing attention on particular issues, affecting voter decisions.
Conclusion
Power Dynamics: Understanding the power of the median voter, agenda setters, and media is crucial in predicting election outcomes and legislative decisions.