18.S996 Social Choice and Social Networks : Spring 2018

Professor: Elchanan Mossel.

Lectures: MW 9:30-11:00 at 2-147

Office hours: TBD

Grader: TBD

Background: Condorcet's Jury Theorem (1785) is an early application of probability theory in the social sciences. It provides a simple mathematical model that shows the advantages of broad pariciptation in societal decision making. The course will look at various models and theoretical results relating to collective decision making starting from Condorcet's jury theorem and reaching current research on social networks and social choice theory. Special interest will be given to modern approaches for quantitative analysis and to computational efficiency. The basic questions relate to the aggregation power of groups, to the power of individuals in determining the outcome of a decision and understanding disagreement.

Topics: The course will discuss two broad topics using involving different area of mathematics:

I. Opinion exchange dynamics on networks. The main interest here is understanding network effects when selfish agents try to optimize or perform inference in a networked enivronment. This part will use models and ideas from discrete probability.

II. social choice theory and some of its quantitative aspects. The main goal here is to analayze strategic aspects of voting, in particular in the case where there are 3 or more alternatives. The main methods used in this area are from combinatorics and discrete Fourier analysis.

Some Links:

Survey: Opinion Exchange Dynamics by Mossel and Tamuz

An earlier version of this class

Prerequisites: Graduate level probability and a solid backgound in combinatorics and algorithms (please let me know if you want to take the class but feel you may be unprepared)