The Impact of Price and Information on Water Consumption

英格兰东南部被环保局归类为严重缺水地区。人口增长将继续增加对水的需求，持续的气候变化意味着居民将不得不应对更干燥的夏季和更频繁的干旱。2010年底，负责汉普郡、苏塞克斯和肯特郡供水的南方水务公司启动了一项名为通用计量计划(UMP)的五年计划，在东南部安装50万个新水表。到2015年底，该区域92%的家庭将使用电表，而目前的电表使用率约为40%。该项目的目的是对联合计划对用水量的影响进行全面分析。特别是，该项目将调查家庭对引入水表收费和宣传运动(由南方水务公司在执行联合计划的同时开展)的行为反应，提高对用水对生态的影响的认识，并提出削减水费的简单方法。由于与南方水务公司达成了一项协议，我们将能够获得一个独特的数据集，其中包含关于用水量的家庭水平信息，以及关于联合用水管理计划执行情况的详细信息。然后，我们将利用UMP的具体特点，通过使用计划评估技术，就定价和信息活动是否对用水量产生重大和持久的影响提供新的、可靠的经验证据。为了全面分析控制用水量的最有效策略，我们亦会调查住户对“颜色编码”账单的行为反应，将客户的用水量与所在地区的平均用水量作比较；更具体地说，为调查水表收费的影响，我们会利用一些住户(约35,000户)在开始缴交水表费用前已取得有关用水量的资料。由于技术原因，这些家庭安装了电表，但没有意识到这一点，继续支付固定费用(即未计表的费用)。为了调查宣传活动的影响，我们将利用这样一个事实，即南方水务公司与人民运动联盟一起，在五年内开展了非常本地化的(街头)宣传活动，提供有关用水对生态影响的信息。由于这些活动也影响到已经计量的家庭，他们在定价方面没有任何变化，我们将能够隔离信息的影响。最后，我们将利用颜色代码随用水量不连续变化的事实，并通过使用回归不连续方法，能够确定同行比较对用水量的因果影响。此外，采用统一的定价表(2012年/2013年期间，每立方米淡水/废水的统一成本为3.058 GB)可能会对用水公平产生负面影响。鉴于更富裕的家庭往往使用更多的水，美国和澳大利亚的水务公司经常采用提高分段费率定价(当用水量达到一定阈值时，单位成本增加)，以实现一定程度的总用水量减少和改善客户公平的双重目标。在我们的分析中，我们将能够根据家庭的富裕程度来区分UMP对用水的影响。然后，我们将能够讨论统一定价时间表对股权的影响。

The South East of England has been classed by the Environmental Agency as an area of severe water stress. Population growth will continue to increase the demand for water and on-going climate changes mean that residents will have to deal with drier summers and more frequent droughts. At the end of 2010 Southern Water, the utility responsible for supplying water in Hampshire, Sussex and Kent, started a five-year program, known as Universal Metering Program (UMP), to install half a million new water meters in the South East. By the end of 2015, ninety-two per cent of the households in this region will be metered, compared to the current rate of about forty per cent. The aim of this project is to produce a comprehensive analysis of the impact of the UMP on water consumption. In particular, this project will investigate the behavioural response of households to the introduction of metered charges and to the information campaigns (run by Southern Water while implementing the UMP) raising awareness about the ecological impact of water consumption and suggesting simple ways to cut the water bill. Thanks to an agreement with Southern Water, we will have access to an unique dataset containing household level information on water consumption, together with detailed information about the implementation of the UMP. We will then exploit specific features of the UMP to produce, by using program evaluation techniques, fresh and sound empirical evidence on whether pricing and information campaigns have a significant and long-lasting impact on water consumption. In order to produce a comprehensive analysis of the most effective strategies to contain water consumption, we will also investigate the behavioural response of households to "colour-coded" bills comparing customers' water consumption to the average consumption in their neighbourhood.More specifically, to investigate the impact of metered charges, we will exploit the fact that for some households (approximately 35,000) information on water consumption is available before they start paying metered charges. These households have had a meter installed for technical reasons, but are not aware of this and continue paying a fixed fee (i.e unmetered charges). To investigate the impact of information campaigns, we will exploit the fact that Southern Water is running, in conjunction with the UMP, very localized (street-level) campaigns over a five-year period providing information about the ecological impact of water usage. As these campaigns also affect already metered households, who do not experience any change in terms of pricing, we will be able to isolate the impact of information.Finally, we will exploit the fact that the colour-code changes discontinuously with consumption and, by using a regression discontinuity approach, will be able to identify the causal impact of peer comparison on water usage. Furthermore, the introduction of an uniform pricing schedule (for the period 2012/2013, there is a flat cost of £3.058 per cubic meter of fresh-water/waste-water) may negatively affect equity in water consumption. Given that more affluent households tend to use more water, water utilities in USA and Australia frequently use increasing block rate pricing (where the cost per unit increases when consumption reaches certain thresholds) with the dual objective of achieving some reduction in total water use and improving equity among customers. In our analysis we will be able to differentiate the impact of the UMP on water use according to household affluence. We will then be able to discuss how the uniform pricing schedule is affecting equity.