Collective action problem

The collective action problem is when a group of people have something they want to do that would be better for everybody in the group, but it is hard for the group members to agree on how to do it. For example, suppose a class of students all want to save money by buying their textbooks together. They know that if they all buy the books together, they'll get a discount. But if some of the students don't agree or don't contribute to buying the books, the other students don't get the discount. So, the collective action problem is how to get everyone to agree to work together and buy the books together.