Abstract
Recently in Japan it's very important to analyze efficiency of sewage improvement projects for households. But most of research efforts which deal with the efficiency of sewage improvement projects analyze the cost but fail to discuss their benefits. So the purpose of this study is to estimate the net social benefits of sewage improvement projects for households. First, we proposed a new method to estimate benefits of sewage improvement projects based upon hedonic approach supplemented by survey approach before estimating the benefits. Secondly, we estimated the net social benefits of sewage improvement projects in the Tokyo Metropolitan area. We found that net social benefit was negative in KOKUBUNJI CITY. And we found also the net social benefit associated with small scale treatment projects to improve the water quality of the river was lager than that associated with the existing system in MATSUDO CITY.
