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?