Abstract: New tenancy theory refutes the viewpoint referring to sharing contract being inefficient from conventional tenancy theory. In fact, the error of conventional theory is that it has not considered the risk cost in the real world. So, if the risk factor is uniformed into the transactional costs, the efficiency of sharing contract is also proved. Although the regulation of landlord’s rent revenue right will make rent dissipate, the effect of tenants’ competition becomes an incentive to increase their labor inputs and improve gross agriculture production levels. If the transactional cost is divided into exogenous and endogenous these two types, then we can use them to demarcate efficiency boundary of regulation of land right. And the suitable regulation of land right is a rational choice behavior paradigm in which the opportunist minimizes gross transactional costs under the constraint of resource attribute. Therefore, in terms of evolution history of western physiocracy school, new tenancy theory that based on classic and new classic physiocracy economics brought in transactional costs and risk factor, and created a precedent of new physiocracy economics.

摘要： 新佃农理论推翻了传统佃农理论关于分成契约效率低下的观点。其实，传统观点的不严谨之处主要是未能考虑真实世界中的风险费用。所以，只要把风险因素统一到交易费用范畴当中也可证明分成契约的有效性。尽管地主的租金收益权利被管制而造成租金耗散，但佃农之间的竞争效应使得佃农劳动投入增加从而农业总产出提高。若交易费用分为外生性与内生性两种，则可以进一步以此划分地权管制的效率边界，而地权适度管制是具有机会主义倾向的人们在资源属性约束下最小化总交易费用的一种理性选择行为范式。因此，地权管制的程度与范围随着交易费用的转变而改变。最后，从西方重农主义学派的演进历史来看，新佃农理论在古典与新古典重农主义经济学的基础上引入了交易费用与风险因素，开创了新制度重农主义经济学的先河。