According to the “induced innovation model of agricultural development” there exist mechanisms for this sector’s participation in contributing to economic development, as well as in sharing its benefits. Nonetheless, inefficiencies of the market that distort market signals, constitute a barrier of the latter process. Therefore, the so-called “surplus drainage” from agriculture takes place. The authors claim that it is possible to objectively measure a “surplus drainage” from agriculture as a result of market failure. Assuming that rural areas generate public goods (i.e. a landscape, a biodiversity, rural culture and tradition, unique food quality, food safety, food security) speculative land investors have lower willingness to contribute to its creation, than family farms. This is why agrarian policy levies more duties on them (institutional barriers) and favours farmers. The mentioned premises imply that the CAP’s subsidies should not be perceived as political rents according to its classical definition. Only a part of subsidies left after subtracting a value of “surplus drainage” and a compensation of public goods has a hallmark of the rent. A valuation of these values is an important scientific challenge.