The economic activities of government include (1) correcting for equality externalities , (2) providing a property system legal system , (3) promoting oligopolies competition , (4) producing public private goods, and (5) ensuring economywide equality economywide stability . Part 2 The principle of rival consumption identical consumption does not apply to public goods as it does to private goods. Part 3 Public goods have two characteristics: (1) Once they are produced, there is no additional marginal cost opportunity cost when additional consumers use them, because your use of a public good does not deprive others of its simultaneous use; and (2) consumers cannot conveniently be pleased charged on the basis of use