Anti-rival good

An anti-rival good is the opposite of a rival good: it is a good wherein the more people share it, the more utility each person receives. Examples include free software, open source software, and other information goods created through the process of commons-based peer production.

An anti-rival good meets the test of a public good because it is non-excludable (freely available to all) and non-rival (consumption by one person does not reduce the amount available for others). However it has the additional quality of being created by private individuals for common benefit without being motivated by pure altruism, because the individual contributor also receives benefits from the contributions of others. In evolutionary biology, this mode of production and exchange is called reciprocal altruism.

An example is provided by Lawrence Lessig:

It's not just that (open source) code is non-rival; it's that code in particular, and (at least some) knowledge in general, is, as Weber calls it, 'anti-rival'. I am not only not harmed when you share an anti-rival good: I benefit.

—Lawrence Lessig

The production of anti-rival goods typically benefits from network externalities. Leung (2006) offers this quote from Weber (2004):

Under conditions of anti-rivalness, as the size of the Internet-connected group increases, and there is a heterogeneous distribution of motivations with people who have a high level of interest and some resources to invest, then the large group is more likely, all things being equal, to provide the good than is a small group.

—Weber, Leung (2006)

The term is a neologism coined by Steven Weber. Although the term "anti-rival good" is a neologism, this category of goods may be neither new nor specific to the Internet era. According to Lessig, a particular natural language also meets the criteria:

Language is an anti-rival good: not only does your speaking English not restrict me, your speaking it benefits me. The more people who speak a language, the more useful that language is... to those who speak it.

—Lawrence Lessig

The term also invokes Reciprocity (cultural anthropology) and the concept of a gift economy. See also Private good and Good (economics and accounting).

References and further reading

• Lessig, L. "Do You Floss?". London Review of Books. http://www.lrb.co.uk/v27/n16/less01_.html. Retrieved November 14, 2006. 
• Leung, T. "(Review) The Success of Open Source". Sauria Associates. http://www.sauria.com/blog/2006/06/04. Retrieved November 15, 2006. 
• von Hippel, E. (2005), Democratizing Innovation, The MIT Press, ISBN 978-0-262-00274-5 .
• Weber, S. (2004), The Success of Open Source, Harvard University Press, ISBN 978-0-674-01292-9 .
• Federalist Blog: Is Technology a Public Good?