This involves the characteristics of the production human as well as non human using the product concerned. For example it may pertain to the number and characteristics of children in a study of the demand for types. In fact it involves distinguish between the total market demand and market segments. Such segments may be derived in terms of income social status sex age male female ration urban rural ration educational level geographic location etc. The segment when qualified can be used an independent variable affecting the demand of the product in question.