  There is a second feature of Samuelson’s public goods that would make them problematic in practice: the impossibility of exclusion. Once supplied at all, it is supposedly impossible to exclude anyone from the consumption of a public good. It is often noted that this feature is analytically interesting but empirically often beside the point. States often forcibly exclude people from enjoying such public goods as radio broadcasts. Others can be provided through the use of various devices that enable providers to charge the beneficiaries and to exclude those who do not pay, as for example, by advertising that imposes a cost on television viewers or the use of cable rather than broadcasting over the air to provide television programming at a substantial price. Exclusion is merely a problem of technology, not of logic. With present technology, however, it may be too expensive to exclude many people and we may therefore want the state to provide many goods so that we can avoid the costs of exclusion.