Another ecological market failure is presented by the overutilisation of an otherwise renewable resource at a point in time, or within a short period of time. Such overutilisation usually occurs when the resource in question has poorly defined (or non-existing) property rights attached to it while too many market agents engage in activity simultaneously for the resource to be able to sustain it all. Examples range from over-fishing of fisheries and over-grazing of pastures to over-crowding of recreational areas in congested cities. This type of ecological market failure is generally known as the 'tragedy of the commons'. In this type of market failure, the principle of Pareto efficiency is violated the utmost, as "all" agents in the market are left worse off, while nobody are benefitting. It has been argued that the best way to remedy a 'tragedy of the commons'-type of ecological market failure is to establish enforceable property rights politically – only, this may be easier said than done.