Public good: good/service that, to at least some degree, is both non-rival and non-excludable.
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Non-rival good: good whose consumption by one person does not diminish its availability for others.
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Non-excludable good: good that is difficult, or costly, to exclude non-payers from consuming.
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Collective good: good/service that, to at least some degree, is non-rival but excludable.
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Pure private good: one for which non-payers can easily be excluded and for which each unit consumed by one person means one less unit available for others.
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Pure commons good: one for which non-payers cannot easily be excluded and for which each unit consumed by one person means one less unit available for others.
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Regressive tax: tax under which the proportion of income paid in taxes declines as income rises.
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Proportional income tax: one under which all taxpayers pay the same proportion of their incomes in taxes.
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Because the quantity of a public good must be the same for every consumer, the total demand curve for a public good is constructed by adding individual demand curves vertically. Optimal production of a public good occurs at the quantity for which the demand curve intersects the marginal cost curve for the public good.
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Government need not always be the best way to provide public goods. Such goods can be provided by private organizations that rely on charitable contributions or the sale of by-products. Private for-profit companies also can become providers when new technologies such as pay-per-view television convert public goods into collective goods.
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Government creates economic surplus not only by providing public goods but also by regulating activities that generate externalities and by defining and enforcing property rights. These rationales explain why most governments regulate pollution, subsidize education, control access to fishing waters and public timberland, and enforce zoning laws.
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Although the framers of the Constitution disliked centralized government power, they recognized that some government functions are not best performed at the local Or even state level. Economies of scale argue for provision of defense at the national level. Externalities that transcend local boundaries provide an additional rationale for national or even international government.
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Crowding out: government borrowing that leads to higher interest rates, causing private firms to cancel planned investment projects (i.e., the tendency of increased government deficits to reduce investment spending).
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