In the urban drought assumed to be "the tragedy of the commons" situation, residential consumers must decide whether or not to take water conservation behaviors in compliance with the community conservation programs. Survey 1 consisting of 78 consumers with no drought experience was conducted to examine the relationship between consumers' beliefs toward water use and their behaviors. A factor analysis of beliefs revealed three factors; benefit-cost evaluation of water use, perceived effectiveness of water conservation, awareness of social cost of water waste. A regression analysis showed the benefit-cost evaluation factor to be only correlated with water conservation. Survey 2 consisting of 357 consumers with a drought experience, was conducted to clarified the determinants of water conservation at different sequential stages; normal water supply, recommendation of voluntary conservation, rationing of water supply. Analysis of regressions for the different stages revealed difference in regression equations. Especially the benefit-cost evaluations of conveniency, cost effectiveness, and cleanness were correlated with water conservation at the first, second, third stages, respectively. These findings indicate the rank hierarchy of the benefit-cost evaluations of water use.
