In letzter Zeit ist des Öfteren von öffentlichen Gütern (public goods) die Rede, oft im Zusammenhang mit Gütern, die keine öffentlichen Güter sind, wie z.B. Rechten, die gegenüber dem Staat oder anderen Bürgern geltend gemacht werden sollen.
Was sind öffentliche Güter? Wodurch zeichnen sie sich aus? Die beste Antwort auf diese Frage haben nach unserer Ansicht William J. Baumol und Alan S. Blinder bereits im Jahre 1979 gegeben.
“It is easier to explain the nature of public goods by contrasting them with the sort of commodities called private goods, which are at the opposite end of the spectrum. Private goods are characterized by two important attributes. One can be called depletability. If you eat a steak or use a gallon of gasoline, there is that much less beef or fuel in the world available for others to use. Your consumption depletes the supply available for other people, either temporarily or permanently.
But a pure public good is the legendary widow’s jar of oil, which always remained full no matter how many people used it. Once the snow has been removed from a street, the improved driving conditions are available to every driver who uses that street, whether 10 or 1000 cars pass that way. One passing car does not make the road less snow-free for another. The same is true of the spraying of swamps near a town to kill disease-bearing mosquitoes. The cost of spraying is the same whether the town contains 10,000 or 20,000 persons. A resident of the town who benefits from this service does not deplete its advantage to others.
The other property that characterize private goods but not public goods is excludability, meaning that anyone who does not pay for the good can be excluded from enjoying its benefits. If you do not buy a ticket, you are excluded from the ball game. If you do not pay for an electric guitar, the storekeeper will not give it to you.
But some goods or services are such that, if they are provided to anyone, they automatically become available to many other persons whom it is difficult, if not impossible, to exclude from the benefits. If a street is cleared of snow, everyone who uses the street benefits, regardless of who paid for the snowplow. If a country provides a strong military establishment, everyone receives its protection, even persons who do not happen to want it” (Baumol & Blinder, Economics: Principles and Policies, p.619).