Originally posted on Notes On Liberty
Public goods in economics have been a contentious theoretical issue since Paul Samuelson introduced the concept in 1954. The main sources of contention are what real world things are public goods, and who should provide them. In this post I propose a new way of looking at goods that will shed light on why public goods have posed such a problem. In particular, I propose that there is an important distinction between physical goods and immaterial goods; that public goods can only be immaterial goods; and that this unique feature of public goods does not preclude the market to provide the “socially optimal level.
Economists define a public good as something that is “non-rival” (meaning that one person’s consumption does not affect another person’s), and “non-excludable” (meaning that one person cannot stop another person from consuming the good.) Public goods are often contrasted with private goods, which are rival and excludable.
The implications are that public goods cannot be provided by a free market, because no one would have to pay for such a good, and so there would be so incentive to produce it. Therefore, the argument goes, the government ought to provide public goods.