Analytical Framework of Resource Allocation Levels for Agricultural Land Conservation

At the present stage, China's farmland de-farming is mainly started by the government's expropriation of rural collective land, and then the state-owned land use rights are circulated in the primary market through allocation, agreement, bidding, auction, and other transfer methods, and finally the land users transform the land use after obtaining the use rights to complete the de-farming of farmland. In theory, there are three types of prices (Tan Rong et al., 2006b), as shown in Figure 4-1, P3 is the market equilibrium price when the marginal cost of farmland de-agrarianization (MC') includes the cost of eco-efficiency, P2 is the market equilibrium price when the marginal cost of farmland de-agrarianization (MC) does not include the cost of eco-efficiency, and P1 is the market equilibrium price when the transaction is subject to the intervention of some factors (e.g. the government). P1 is the price specific to the process of farmland de-agrarianization in China at this stage, which is generated by the government's intervention in the market of farmland de-agrarianization, and it causes excessive farmland de-agrarianization. So far, we can subdivide the sectoral efficiency loss of farmland de-agrarianization into costly loss, excessive loss I and excessive loss II.

Figure 4-1 Market Price and Quantity Allocation of Agricultural Land

Traditional economics has neglected the ecological and landscape functions of agricultural land, the social and ecological values such as food security and intergenerational equity, and it is precisely these "externality" benefits that are often ignored by the average land user. Considering the marginal cost MSC, the optimal amount of farmland de-agrarianization should be Q3, the corresponding land price should be P3, and the total social welfare should be maximized AEO, at this time, the highest efficiency of farmland de-agrarianization allocation, which is the amount of de-agrarianization under the action of the price mechanism including the internal costs and externalities of farmland de-agrarianization, which is the costly loss of farmland.

For in the competitive market conditions, the normal price of land for the Figure 4-1 P2, the amount of farmland non-agriculturalization for Q2. this time from the landowner, to achieve the optimal allocation of resources, the realization of the private interests of the maximum; but compared with the maximization of the welfare of society as a whole, due to the price of P2 does not respond to the ecological value of the farmland and the value of the community, so at this time, the allocation of the efficiency has not reached the highest, the excessive amount of non-agriculturalization is Q2 - Q2 - Q2, and the amount of non-agriculturalization is Q2 - Q2. agriculturalization over-quantity of Q2-Q3, resulting in a total social welfare loss of EE'F'. This excessive quantity is caused by market failure, i.e., the traditional market system cannot reflect the non-market value of farmland, which is called the loss of excessive non-farming nature of farmland Ⅰ.

If the price of land is affected by some factors and is lower than the price P2, the amount of farmland de-agrarianization will be greater than Q2. as in Figure 4-1, assuming that the price of land is P1, the amount of farmland de-agrarianization will be Q1, at this time, farmland de-agrarianization is the most inefficiently allocated, and the total welfare of the society will be lost EFG, and even for the land users as a whole, the direct loss reaches GE'G'. Compared with the social optimum, the amount of excessive non-agriculturalization is Q1-Q2, which is due to government failure, the market mechanism can not function properly under the formation of the market mechanism, which significantly reduces the efficiency of the allocation of farmland non-agriculturalization, which we call the loss of excessive non-agriculturalization of farmland II.

(I) Sectoral allocation efficiency

For the sectoral allocation efficiency, if we regard the marginal return of land resources in the non-agricultural sector as the marginal return of farmland de-agriculturalization, and its marginal return in the agricultural sector as the marginal cost of farmland de-agriculturalization, we can use the most basic marginal return and marginal cost curve diagram to represent the optimal allocation of land resources in the two sectors. As shown in Figure 4-1, the optimal amount of farmland to be de-agriculturalized is Q2 if only private costs are considered, and Q3 if social costs are considered. any amount of farmland de-agriculturalized in excess of the costly loss is a loss in allocative efficiency.

(II) Spatial allocation efficiency

For spatial allocation efficiency, due to the vastness of China, the optimal social benefit of farmland de-agrarianization is not only the maximization of social benefit in local areas, but more importantly, it is the ability to achieve the optimal spatial allocation efficiency in the whole country. Existing farmland de-agrarianization ignores the existence of spatial differences, resulting in inefficient spatial allocation of farmland de-agrarianization. China's farmland de-agrarianization is mainly guided by the overall land use planning, although the existing target level by level decomposition system has effectively controlled the sharp decline of farmland resources and ensured the implementation of land use control in the initial stage, but with the increasingly obvious gap between the economic development of different regions, this planned target rationing system has gradually become a shackle for the efficient use of land resources. Because it does not take into account the unbalanced nature of regional economic development and natural resource endowment, and does not carry out the spatial allocation of land resources according to the principle of balanced spatial efficiency.

The spatial allocation of resources is one aspect of resource allocation, and any textbook on resource economics elaborates in detail the principle of spatial allocation of resources---equal marginal efficiency of resource utilization in different spaces is the only principle of optimal spatial allocation of resources. That is, as long as the marginal benefits of resource utilization in different geographical areas are equal, the overall maximization of the benefits of resource utilization can be ensured. Otherwise, there is the possibility of inter-geographical flow of resources, and the overall utilization of resources exists Pareto improvement. Therefore, at this stage, the spatial configuration of China's farmland de-agrarianization should also follow this principle, only to ensure that the marginal benefits of each region's farmland de-agrarianization are equal, in order to meet the national farmland de-agrarianization of the spatial configuration of the maximization of efficiency.

(III) Time allocation efficiency

Resources, especially non-renewable resources, are limited in quantity making the efficiency of allocation between generations (time) more important. The configuration of the non-agriculturalization of agricultural land resources in the intergenerational, is reflecting the characteristics of the intergenerational allocation of non-renewable resources. Farmland de-farming refers to the process of farmland resources being used for non-farm construction land development and utilization, due to the huge cost of restoring the developed and utilized farmland to farmland in terms of technology and cost, which makes it possible to consider farmland de-farming to a certain extent as having the characteristics of non-renewable resource utilization. In China, the per capita agricultural land resources are very scarce, and agricultural land is mostly the development and utilization of agricultural land resources, although in order to economic development needs agricultural land de-agriculturalization, but at this stage of agricultural land de-agriculturalization is only in line with the optimal use of its society in order to achieve the protection of resources and the coordination of economic development. At the present stage, the process of farmland de-agrarianization has serious excessive loss of farmland resources due to the unsoundness of the market allocation method in the allocation process and the inappropriate intervention of the government. There have been some studies focusing on the efficiency loss caused by the process of farmland de-agrarianization, but few studies focus on the efficiency loss on the intergenerational allocation of farmland de-agrarianization. Leaving aside the fact that intergenerational allocation has to take into account the fairness of the utilization of resources by future generations, only from the point of view of efficiency, if we do not pay attention to the temporal allocation efficiency in the utilization of resources, it will inevitably produce short-term behavior in the utilization of resources, resulting in the excessive depletion of limited resources.

Theoretically, the study of intergenerational allocation of resources has been quite mature, resource economics textbooks give the optimal model of intergenerational allocation of resources, the conclusion of these models is that as long as to meet the utilization of resources in the intergenerational marginal returns between the present value of the equality of resources to ensure the optimal intergenerational allocation of resources. However, these theoretical models do not provide us with the method of how to calculate the marginal revenue of resource utilization in reality, which causes the disconnection between theory and practice. Most of the foreign studies in this area are calculated from the perspective of cost-benefit analysis, assumptions are made about future resource utilization returns and discount rates, and the optimal amount of allocation in each period is obtained by measuring the total return stream of resource utilization and then making the determination of the maximum return, which inevitably leads to the problem of subjective estimation error. Therefore, there is a need to find a method suitable for calculating and evaluating whether the current stage of farmland de-agrarianization in China is in line with the intergenerational allocation efficiency.