Cairncross S, Kinnear J
London School of Hygiene and Tropical Medicine, U.K.
Soc Sci Med. 1992 Jan;34(2):183-9. doi: 10.1016/0277-9536(92)90095-8.
A survey of the quantities of water purchased from vendors in the squatter areas of Khartoum, Sudan, was used to assess the effect of the price charged for water and of household income on domestic water consumption. Households in two squatter communities--Meiyo and Karton Kassala--were studied by observation and by interview. In spite of the substantially higher charges, water consumption in Karton Kassala was as high as that in Meiyo. Households within these communities showed no tendency to use less water when paying a higher price for it, or when their income was below average. In other words, no price elasticity or income elasticity was detectable. This was all the more striking in view of the high proportion of income that was spent on water; 17% in Meiyo, and 56% in Karton Kassala. One consequence of this lack of elasticity is that the poorest households devote the greatest percentage of their income to the purchase of water, although the only major item in their household budget which can be sacrificed to make this possible is food. The high price of water in urban Sudan is probably a major cause of the malnutrition prevalent in the squatter areas. Another consequence is that a low-income household's consumer surplus for domestic water is very high, amounting to a substantial proportion of its total income. This has important consequences for the economic appraisal of urban water supply schemes. It also follows that wealthier households with private connections would be willing to pay at least as much for water as that currently paid by the poor.
对苏丹喀土穆棚户区从商贩处购买的水量进行了一项调查，以评估水价和家庭收入对家庭用水量的影响。通过观察和访谈对两个棚户区社区——梅约和卡尔顿·卡萨拉的家庭进行了研究。尽管卡尔顿·卡萨拉的水价要高得多，但那里的用水量与梅约一样高。这些社区内的家庭在支付更高水价或收入低于平均水平时，没有减少用水量的趋势。换句话说，没有发现价格弹性或收入弹性。鉴于用于水的支出占收入的比例很高，这一点就更加引人注目了；在梅约为17%，在卡尔顿·卡萨拉为56%。这种缺乏弹性的一个后果是，最贫困的家庭将其收入的最大比例用于购买水，尽管他们家庭预算中唯一可以牺牲以实现这一点的主要项目是食物。苏丹城市地区水价高昂可能是棚户区普遍存在营养不良的一个主要原因。另一个后果是，低收入家庭的家庭用水消费者剩余非常高，占其总收入的很大比例。这对城市供水计划的经济评估具有重要影响。由此还可以推断，有私人供水管道的较富裕家庭愿意为水支付至少与穷人目前支付的价格一样多的费用。
