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

Social Choice and Voting



Département : Economics


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