The study aims at demonstrating the core principles to be implemented for protected transactions in developing and transitional countries to trigger economic development. Two approaches are discussed which claim having demonstrated that the institution of property is the most important source of economic activity: (i) the theory of property rights or new institutional economics and (ii) the property theory of the economy or property economics. Both schools, and (iii) reform programs of multilateral institutions based on the schools' approaches, are analyzed from the viewpoint of the dichotomy between property and possession.