Open source licenses are noted for being self-referential. The two dominant licenses at the early stage of the open source movement were GPL and BSD. GPL says the next developer cannot go proprietary, and can only go open source with the same license, namely GPL. BSD says the next developer can go proprietary, and can also go open source with any open source license, including BSD. We construct the universal space of all self-referential licenses such as GPL and BSD. We also provide a plausible explanation of why GPL and BSD stood out from other licenses as the two most natural choices for the first-generation open source developers.

In analyzing how to allocate assets between two trading partners, the PRT depends on the ability of these two traders in obtaining payoffs by trading in a outside market and the dependence of these outside payoffs on property rights. This begs the questions: i) how can the outside market clear and serve the two traders at the same time? and ii) how are the payoffs determined in the outside market? We reconstruct the PRT formulation in a market with multiple traders on both sides, making relationship-specific investment before they compete and form efficient assignment. The disagreement payoffs are the corresponding Walrasian prices. When PRT-type equilibrium exists, the benefit of asset ownership in alleviating under-investment inside the match is necessarily accompanied by the cost of aggravating the over-investment specific to alternative partners. In two simplified versions of the model, we derive conditions for the existence of PRT equilibrium and analysis the short-run effects of various types of vertical and lateral integration. We also characterize long-run PRT equilibrium when assets can be purchases in a competitive market and explain the distortion caused by incomplete contract and relationship specificity of investment.