What is meant by the tragedy of the commons? Use an example to explain your answer

What will be an ideal response?

The tragedy of the commons refers to the depletion of a common pool resource due to open access. When deciding how much to use, everyone using the common pool resource considers only his or her own costs of use. But this use depletes the resource for everyone accessing it. Since this extra cost is external, individuals end up using too much of the resource. Congested roads without tolls are a good example of the tragedy of the commons. People who use the road consider their benefits but ignore the costs they impose on other drivers by forcing them to drive more slowly.