ENSAE Paris - École d'ingénieurs pour l'économie, la data science, la finance et l'actuariat

Social Choice and Voting


This course aims to study normative and strategic analysis of social decision making. Collective decision making is ubiquitous and plays a crucial role in our society. In normative analysis, we learn desirable properties of the decision rules when individual preferences are aggregated to a collective decision. In strategic analysis, we learn how the quality of collective decisions depends on decision rules inducing a various types of incentives at the individual level. Students are expected to learn theories as well as a variety of applications in real-life examples. A leading example will be voting, which plays a foundational role not only in democratic but also economic and political decision makings.


  • Social choice theory: 

Arrow’s model, social choice function, social welfare function
Strategy-proofness (Gibbard-Satterthwaite)
Comparing voting rules (simple majority, Borda, Condorcet, Approval voting, Majority judgment)

  •  Collective decision making:

Information aggregation
Condorcet Jury Theorem
Poisson Games (and other refinement models)
Apportionment problems

  •  Strategic voting:

Rational voting models
Group-based models
Testing rationality


Moulin (1988) “Axioms of Cooperative Decision Making,” Econometric Society Monographs, Cambridge University Press
Myerson (1997) “Game Theory : Analysis of Conflict,” Harvard University Press