Some markets can fail due to the nature of the goods being exchanged. For instance, some goods can display the attributes of public goods or common goods, wherein sellers are unable to exclude non-buyers from using a product, as in the development of inventions that may spread freely once revealed, such as developing a new method of harvesting. This can cause underinvestment because developers cannot capture enough of the benefits from success to make the development effort worthwhile. This can also lead to resource depletion in the case of common-pool resources, whereby the use of the resource is rival but non-excludable, there is no incentive for users to conserve the resource. An example of this is a lake with a natural supply of fish: if people catch the fish faster than the fish can reproduce, then the fish population will dwindle until there are no fish left for future generations.