A maximum probability model is applied to evaluate the effects of adoption of new technology and introduction of hired labor in a vegetable farming system in Chiba, Japan. The model incorporates farmer's aspiration level (risk preference parameter), fluctuation of revenue coefficients, and limitation of resources. The following are main results : 1) Adoption of new cultivation technology by prefabricated greenhouse, which has vinyl walls and a vinyl roof instead of glass, increases both expected value and stability of the total revenue with increase of family labor inputs. 2) Introduction of hired labor to the farming system with new technology contributes mainly an increase of expected revenue in risk-neutral (higher aspiration level) case and mainly an increase of stability of revenue in risk-averse (lower aspiration level) case. 3) Risk preference (value of aspiration level) affects the optimal size of the greenhouse when hired labor inputs are available.

　At present, paddy field rearrangement is necessary to decrease the costs of rice production in the Tohoku district. Because it is important to achieve consensus among farmers before starting the rearrangement project of paddy fields, the aim of this study is to clarify factors which affect farmers' agreements to rearrangement projects. The study particularly concentrates on the case of Toyosatocho, located in a typical rice production area in Miyagi prefecture, and we apply the logit model.
　The potential cost reductions from the project is the greatest incentive for farmers' agreements to the paddy field rearrangement project. Town officials found a special method of cost reduction in the case of Toyosatocho. There is a national project that prevents water from filling up paddy fields. This project improves the drainage system. By introducing this project, farmers can save on the cost of rearrangement because the central and local governments subsidize the cost of project.
　Then, we found that farm scale and man-machine ratio are two major important factors. The rate of agreement to rearrangement project is in proportion to these factors. The scatter of paddy field is also an important factor which affects the farmers' agreements.
　Further, we clarified that local government's human resource allocation is an important factor in increasing the rate of agreement to paddy field rearrangement. To increase the agreement rate, the local government should allocate its human resources in achieving consensus among farmers.

　The purpose of this paper is to give a quantitative analysis for the change of factor input relationship caused by the recent increase of wheat preference by the large-scale dry farms in Tokachi, Hokkaido, and to clarify an economic rationality of crop selection from the aspect of the factor input and land utilization. The main points mentioned in this paper are as follows :
　1) The increase of wheat acreage caused the ratio of fee cost in the management cost to shift upward because of a need for collective action in the wheat harvest and dry processing. This can be understood as progress of external activity in the dry farming management.
　2) We set up a management function which consists of two production processes―land-using process and profit-realization process―and analyze change of the factor input relationship.
　3) The results point out that the larger the land scale, the greater the preference for wheat, and the economy of scale is gradually increasing in recent years, which suggests that the economy of scale mainly comes from the wheat preference. However, the increase of wheat, whose price is supported by the government with little reflection of market conditions and higher fluctuation of wheat yield under bad weather conditions, has weakened the original income compensation effect in a poor harvest year.
　4) We estimate the marginal cost of the planting ratio of major crops. The result shows that the increase of wheat ratio exerts a saving effect on management cost, which can be considered as a defensive performance by way of crop selection under the depressive price policy era.

　In this paper, the price policy and the income policy to establish the rational crop rotation system are discussed. At first, consumers' surplus and producers' surplus do not always increase when the above system is adopted in place of the usual cropping system based on market price, because the usual market equilibrium point cannot be achieved under the crop rotation system. And the price policy is problematic in that it is very difficult to decide appropriate price ratios among crops under the crop rotation system. In order to decide the ratios, it is necessary to ascertain the production-possibility frontier curve of each farm correctly ; but this is not possible. On the other hand, the income policy has a problem, too. Under the income policy, it is difficult to ascertain the past realizable income level of each farm. Unless the income level can be grasped, unintended governmental expenditure becomes necessary.
　These policies are thus not effective in establishing the rational crop rotation system. In order to improve farms, technological development is very important. Under this development, producers' surplus definitely increases, Therefore it is important for farm business administration to focus on technological development.

　There were various sizes of landlord domains in the rice monoculture area, which was the core of the landlordism in Japan. Many researchers have analyzed the landlord-tenant relations in the Shonai plain, but researchers' opinions on their historical characteristics are not consistent with each other. The aim of this paper is to clarify characteristics of the landlord-tenant relations in the Later Edo period, by case study of Hisizu-mura in the southern part of Shonai.
　I therefore surveyed aspects of the differentiation of peasantries, and analyzed a small landlord farm management that belonged to the wealthy peasantries. The major results of this analysis are as follows.
　1) The entry areas on the land surveying books were different from the actual ones. The term "nawanobi" refers to the difference between the registered area and the actual area.
　2) Under the high feudal rent in kind, it was very profitable to hold "nawanobi." The wealthy peasantries and the merchants accumulated "nawanobi."
　3) The merchant-landlords got a large quantity of farm rent in kind from "nawanobi." On the other hand, the wealthy peasantries cultivated "nawanobi" to obtain high profits, and leased out other parts of their holding.
　4) The quantity of farm rent in kind, so-called "watariguchimai" which characterized the landlord-tenant relations in this period, was estimated by "karimoto." The "karimoto" were the number of harvested riceplants that indicated the actual area of paddy field.