抄録
A project is judged potentially worthwhile if, in terms of the discounted value of the future stream, its benefit exceeds its cost. The benefit may not be capable of quantification in pecuniary terms, while the cost will be measured in terms of the actual money cost of the project. Such a standard of judgment should be applied to programs to increase green in urban residential areas, provided that the quantification problem is solved by some means or other.
When a household chooses a residential land, it takes account of its neighborhood setting. Since the rent of a land is supposed to be a function of its environmental attributes as well as its site characteristics, the valuation of the environmental attributes of a household can be derived from the relation. The purpose of this paper is to utilize the hedonic approach to estimate the benefit of a tree-planting project.
Cross-sectional data for Nagoya City for 1985 are employed. A program to raise a tree cover ratio to the level of 20 percent is taken up. Indices of environmental characteristics including the ratio are reported at the elementary school district level. The results indicate that the benefit of a household is 12 million yen on an average and that the school districts' benefits range from 3 to 58 billion yen. The project seems to be worth undertaking in the sense that it may possibly have great merit, although the evaluation of the program with more confidence needs cost-benefit analysis.
