<P> Elinor Ostrom proposed additional modifications to the classification of goods to identify fundamental differences that affect the incentives facing individuals (1) Replacing the term "rivalry of consumption" with "subtractability of use". (2) Conceptualizing subtractability of use and excludability to vary from low to high rather than characterizing them as either present or absent . (3) Overtly adding a very important fourth type of good--common - pool resources--that shares the attribute of subtractability with private goods and difficulty of exclusion with public goods . Forests, water systems, fisheries, and the global atmosphere are all common - pool resources of immense importance for the survival of humans on this earth . (4) Changing the name of a "club" good to a "toll" good since many goods that share these characteristics are provided by small scale public as well as private associations . </P> <P> The definition of non-excludability states that it is impossible to exclude individuals from consumption . Technology now allows radio or TV broadcasts to be encrypted such that persons without a special decoder are excluded from the broadcast . Many forms of information goods have characteristics of public goods . For example, a poem can be read by many people without reducing the consumption of that good by others; in this sense, it is non-rivalrous . Similarly, the information in most patents can be used by any party without reducing consumption of that good by others . Official statistics provide a clear example of information goods that are public goods, since they are created to be non-excludable . Creative works may be excludable in some circumstances, however: the individual who wrote the poem may decline to share it with others by not publishing it . Copyrights and patents both encourage the creation of such non-rival goods by providing temporary monopolies, or, in the terminology of public goods, providing a legal mechanism to enforce excludability for a limited period of time . For public goods, the "lost revenue" of the producer of the good is not part of the definition: a public good is a good whose consumption does not reduce any other's consumption of that good . </P> <P> Debate has been generated among economists whether such a category of "public goods" exists . Steven Shavell has suggested the following: </P> <P> when professional economists talk about public goods they do not mean that there are a general category of goods that share the same economic characteristics, manifest the same dysfunctions, and that may thus benefit from pretty similar corrective solutions...there is merely an infinite series of particular problems (some of overproduction, some of underproduction, and so on), each with a particular solution that cannot be deduced from the theory, but that instead would depend on local empirical factors . </P>

Which of the following is an example of public provision​