What is the Tragedy of the Commons?
There is one pasture open to all herdsman in the community. If each herdsman tries to put the maximum number of cattle in said pasture to benefit himself, the pasture will become over-grazed and no one will benefit. The solution is to put limitations for each herdsman on proper use of the pasture. Today, our "commons" are air, water, and other parts of the environment that people must share. To protect these resources the government sets limitations.