Public provision of a private good: What is the point of the BSD license?

Software is a potentially excludable public good. It is possible, at some cost, to exclude non-paying users from its consumption by using copyright law or technological restraints. Licensing the software under proprietary license terms makes of it a private good, licensing it under the BSD does not change the economic nature of the software while licensing it under the GPL artificially makes of it a pure public good. A project leader will prefer one or the other of those license terms depending on her software project’s market potential and on the cost of developing it. The optimal licensing for a sequence of cumulative innovations and the impact of possible competition between rival software development teams are considered.