14 January 2014A theoretical framework combining the two branches of TCE, i.e., the governance branch (Williamson 2005) and the measurement branch (Barzel 2005) may explain the choice of the governance structure for private environmental transactions. Four case studies, i.e., the market for pure air in polluted cities, the contractual arrangement between La Esperanza and the Monteverde Conservation League, the case of the French mineral water bottler Vittel and the case of land ownership by land trusts are briefly developed in order to support the theoretical framework. Special attention is devoted to the presence (or not) of a 3-D (defined, defended and divestible) property rights system in interaction with the juridical system (civil law vs. common law) and its influence on the way environmental property rights are likely (or not) to be re-arranged. Lessons and policy implications are drawn in order to foster research on these challenging issues.