The mass and economic balance of wastes and by-products produced by the industrial cluster centered on cement and concrete products was investigated. In an industrial process that produces various outputs and associated wastes and by-products, the carbon dioxide emissions, for example, can be allocated in two ways. One is a routine allocation determined by the amount of each output, and the other is a modified allocation that uses the economic value of each output, including that of the wastes and by-products. These two methods are compared. The results of the proposed new method using economic values are satisfactory, although there are some imperfections of a routine life cycle inventory including the usual “Process Analysis” and “Input-Output Analysis”. Use of this new allocation method based on economic values might also provide impetus for more effective use of wastes and by-products in various industrial processes.