The paper by Eric von Hippel and Georg von Krogh explores the phenomenon of open source software development and its implications for innovation models in organization science. Open source software is characterized by users freely programming and sharing solutions to technical problems, often without seeking private returns from selling the software. This model combines elements of both the "private investment" and "collective action" innovation models, offering a "private-collective" approach that can provide the best of both worlds under many conditions. The authors highlight two key deviations from traditional innovation models: first, that software users, rather than manufacturers, are typically the innovators in open source projects; and second, that users freely reveal their innovations without expecting private returns. They argue that these deviations are driven by the private benefits users gain from participating in open source projects, such as learning, enjoyment, and a sense of ownership. The paper also discusses the implications of open source projects for governance and collective action, suggesting that the self-provision of private rewards by contributors can reduce the need for central authority and selective incentives. The authors propose that open source software development can serve as a valuable research site for understanding innovation models and the dynamics of collective action.The paper by Eric von Hippel and Georg von Krogh explores the phenomenon of open source software development and its implications for innovation models in organization science. Open source software is characterized by users freely programming and sharing solutions to technical problems, often without seeking private returns from selling the software. This model combines elements of both the "private investment" and "collective action" innovation models, offering a "private-collective" approach that can provide the best of both worlds under many conditions. The authors highlight two key deviations from traditional innovation models: first, that software users, rather than manufacturers, are typically the innovators in open source projects; and second, that users freely reveal their innovations without expecting private returns. They argue that these deviations are driven by the private benefits users gain from participating in open source projects, such as learning, enjoyment, and a sense of ownership. The paper also discusses the implications of open source projects for governance and collective action, suggesting that the self-provision of private rewards by contributors can reduce the need for central authority and selective incentives. The authors propose that open source software development can serve as a valuable research site for understanding innovation models and the dynamics of collective action.