Making Better Group Decisions: Voting, Judgement Aggregation and Fair Division

3.5
Join & Subscribe
Coursera
Free Online Course (Audit)
English
Certificate Available
7 weeks long, 1-3 hours a week
selfpaced

Overview

Much of our daily life is spent taking part in various types of what we might call “political”procedures. Examples range from voting in a national election to deliberating with othersin small committees. Many interesting philosophical and mathematical issues arise whenwe carefully examine our group decision-making processes. 

There are two types of groupdecision making problems that we will discuss in this course. A voting problem: Supposethat a group of friends are deciding where to go for dinner. If everyone agrees on whichrestaurant is best, then it is obvious where to go. But, how should the friends decide whereto go if they have different opinions about which restaurant is best? Can we always find achoice that is “fair” taking into account everyone’s opinions or must we choose one personfrom the group to act as a “dictator”? A fair division problem: Suppose that there is a cake anda group of hungry children. Naturally, you want to cut the cake and distribute the piecesto the children as fairly as possible. If the cake is homogeneous (e.g., a chocolate cake withvanilla icing evenly distributed), then it is easy to find a fair division: give each child a piecethat is the same size. But, how do we find a “fair” division of the cake if it is heterogeneous(e.g., icing that is 1/3 chocolate, 1/3 vanilla and 1/3 strawberry) and the children each wantdifferent parts of the cake? 

Syllabus

Week 1:  Voting Methods    The Voting Problem    A Quick Introduction to Voting Methods (e.g., Plurality Rule, Borda Count,  
          Plurality with Runoff, The Hare System, Approval Voting)        Preferences     The Condorcet Paradox    How Likely is the Condorcet Paradox?    Condorcet Consistent Voting Methods    Approval Voting    Combining Approval and Preference    Voting by Grading
Week 2: Voting Paradoxes    Choosing How to Choose    Condorcet's Other Paradox    Should the Condorcet Winner be Elected?    Failures of Monotonicity    Multiple-Districts Paradox    Spoiler Candidates and Failures of Independence    Failures of Unanimity    Optimal Decisions or Finding Compromise?    Finding a Social Ranking vs. Finding a Winner
Week 3: Characterizing Voting Methods    Classifying Voting Methods    The Social Choice Model    Anonymity, Neutrality and Unanimity    Characterizing Majority Rule    CharacterizingVoting Methods    Five Characterization Results    Distance-Based Characterizations of Voting Methods    Arrow's Theorem    Proof of Arrow's Theorem    Variants of Arrow's Theorem
Week 4: Topics in Social Choice Theory    Introductory Remarks    Domain Restrictions: Single-Peakedness    Sen’s Value Restriction    Strategic Voting    Manipulating Voting Methods    Lifting Preferences    The Gibbard-Satterthwaite Theorem    Sen's Liberal Paradox
Week 5: Aggregating Judgements    Voting in Combinatorial Domains    Anscombe's Paradox    Multiple Elections Paradox    The Condorcet Jury Theorem    Paradoxes of Judgement Aggregation    The Judgement Aggregation Model    Properties of Aggregation Methods    Impossibility Results in Judgement Aggregation    Proof of the Impossibility Theorem(s)
Week 6: Fair Division     Introduction to Fair Division    Fairness Criteria    Efficient and Envy-Free Divisions    Finding an Efficient and Envy Free Division    Help the Worst Off or Avoid Envy?    The Adjusted Winner Procedure    Manipulating theAdjusted Winner Outcome
Week 7:  Cake-Cutting Algorithms    The Cake Cutting Problem   Cut and Choose    Equitable and Envy-Free Proocedures   Proportional Procedures   The Stromquist Procedure   The Selfridge-Conway Procedure   Concluding Remarks

Taught by

Eric Pacuit

Tags

usa