Collective action occurs when a group of people works together to achieve a common goal. This can be done through formal organizations, such as unions or political parties, or informally, such as through social movements.

There are four key elements to collective action:

1. Goal: There must be a shared goal that the group is working towards.

2. Group size: The group must be large enough to have a significant impact.

3. Coordination: The members of the group must be able to coordinate their efforts in order to work effectively towards the goal.

4. Collective action dilemma: There must be an incentive for individuals to participate in the group, despite the costs of doing so.

The collective action problem is a key challenge in economics and occurs when individuals acting in their own self-interest do not produce the best outcome for the group as a whole. This can happen because of free riding, where individuals benefit from the efforts of others without contributing themselves, or because of coordination problems, where it is difficult to get everyone to work together effectively.

Collective action can be an effective way to overcome these challenges and create positive outcomes for a group of people. When done correctly, it can lead to improved economic conditions, better public services, and greater political representation.