由于在电力、有线通信、铁路运输、煤气和自来水供应等自然垄断性产业中的经营企业拥有相当大的市场垄断力量，如果不存在任何外部约束机制，这些企业就有可能通过制定大大高于成本的垄断价格，把一部分消费者剩余转化为生产者剩余，以取得垄断利润，其结果必然扭曲社会分配效 Owing to the considerable market monopoly power by firms operating in natural monopoly industries such as electricity, wireline communications, rail transport, gas and water supply, and without any external restraint mechanisms, it is possible for these enterprises to set a new threshold by setting costs well above cost Of the monopoly price, some of the consumer surplus into surplus producers to obtain monopoly profits, the result will inevitably distort the social distribution of efficiency