4: Social Choice Theory: Two Options Flashcards
What does Condorcets Jury Theorem state?
{voting for information gathering}
if every voter is independently correct with p>0.5, the probability of correct judgement using majority rule aproaches 1 as n→∞ (quickly)
What does Mays Theorem state?
{voting to derive a social preference}
Majority voting is the only SWF that satisfies
1. symmetry among agents
2. neutrality between alternatives
3. positive responsiveneess
What does symmetry among candidates mean?
If the candidates are permutated,the result remains the same
What does neutrality between alternatives mean?
If the alternatives are switched, the result is switched
What does positive responsivenis mean?
If every single one prefers a over b, the SWF will choose a over b