Open source software: Motivation and restrictive licensing

Open source software (OSS) is an economic paradox. Development of open source software is often done by unpaid volunteers and the “source code” is typically freely available. Surveys suggest that status, signaling, and intrinsic motivations play an important role in inducing developers to invest effort. Contribution to an OSS project is rewarded by adding one’s name to the list of contributors which is publicly observable. Such incentives imply that programmers may have little incentive to contribute beyond the threshold level required for being listed as a contributor. Using a unique data set we empirically examine this hypothesis. We find that the output per contributor in open source projects is much higher when licenses are less restrictive and more commercially oriented. These results indeed suggest a status, signaling, or intrinsic motivation for participation in OSS projects with restrictive licenses.