The tragedy of the commons highlights the conflict between individual and collective rationality. The idea was made popular by Garret Hardin, who used the analogy of ranchers grazing their animals on a common field. When the field is not over capacity, ranchers may graze their animals with few limitations. However, the rational rancher will seek to add additional livestock, thereby increasing profits. Thinking logically but not collectively, the benefits of adding additional animals adhere to the rancher alone, while the costs are shared. The tragedy is that ultimately no rancher will be able to graze the field due to overconsumption. This scenario is played out on a daily basis in numerous instances, having grave consequences for the world’s resources.  

Examples of the tragedy of the commons cover several levels. Neighboring cities may seek to maximize their benefits by competing for industry but minimize their costs by pushing residents outside their jurisdictions. In an office, the common space may be the dirtiest compared to individual desks, because of lack of incentive to clean it since those who do not clean could effortlessly benefit from the clean space. 

The mechanisms to resolve these tragedies are part of a larger set of theories dealing with social dilemmas. Scholars have identified and structured a number of tentative solutions, such as enclosing the commons by establishing property rights, regulating through government intervention, or developing strategies to trigger collective behavior. Eleanor Ostrom argued that these strategies generally deal with problems of commitment and problems of mutual monitoring.  

Edited by Dianzhuo ZHU, adapted from Bevir, M. (2007). Encyclopedia of governance. Sage. pp979