From P2P Foundation

Mark Cooper:

"A public good exhibits Nonrivalry in consumption and Nonexcludability. When producers cannot exclude individuals from consuming their good, the individuals using the good for free may withhold their support for the good, seeking a free ride. Where the costs of exclusion are high, the cost may outweigh the value of the good. This prevents producers from providing public goods, even when those goods are beneficial to the public." (http://cyberlaw.stanford.edu/system/files/From+Wifi+to+Wikis+and+Open+Source.pdf)

More Information

1. Common Property, Collaborative Goods
2. Private Goods, Public Goods, Common Pool Resources
3. Property