Regulation under Asymmetric Information in Water Utilities
Regulation under Asymmetric Information in Water Utilities
复制标题
水务公司信息不对称的监管
DOI：
10.1257/000282806777212369
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
I. Perrigne
中科院分区：
文献类型：
--
作者：
I. Brocas;K. Chan;I. Perrigne
水务公司让人想起网络行业，其特点是重要的固定成本。这些因素促使单一公司服务于一个领域，证明公共干预定价是合理的。大约四分之一的美国水务公司是私营的，受监管。监管机构不太可能完全了解情况，监管也不太可能无成本地实施。这些内在的不完善导致经济学家使用信息经济学来考虑监管程序的激励特性（见David Baron， 1989）。根据Paul L. Joskow和Nancy L. Rose（1989）的调查，关于监管的实证文献集中于评估监管对航空、电力和能源等行业的价格、企业成本、效率和创新的影响。这些实证研究很少依赖于所谓的监管理论。关于水务行业，鉴于其公私性质，有大量关于居民用水需求、公司成本和效率的文献。Frank a . Wolak（1994）基于一个信息不对称的模型，以加州自来水公司为样本，评估了由于信息不对称导致的消费者福利损失，并表明信息不对称的模型比完全信息下的模型更能描述成本和需求数据。分析居民用水价格是一个重要的政策问题，因为该行业最近经历了价格上涨。这个问题在加州更为严重，因为随着人口增长、水资源短缺和严重干旱的可能性，居民对水的需求很高。根据1995-2000年期间加州32个地区的新数据集，我们分析了私人水务公司的监管。加州公用事业委员会（CPUC）为每个地区选择水价、每米的使用费和资本回报率，以满足公司的收入要求。我们假设CPUC不完全了解企业的劳动效率。继David Besanko（1984）和Wolak（1994）之后，我们开发了一个模型，其中公司的资本被用作筛选变量。特别是，该模型具有收益率调控的特点。我们展示了如何最优地确定回报率和访问费以控制企业的租金。然后，我们采用结构化方法来分析数据。多步估计器允许我们估计模型的关键参数。实证结果显示价格不弹性、收入效应、规模收益略下降、高效企业集中。最优回报率和访问费用的计算表明，CPUC将倾向于谨慎地允许低于最优的回报率和访问费用。根据估计的参数，第一个实验评估了信息不对称的代价。价格会显著降低，导致消费者剩余增加。第二个实验是按照Farid Gasmi等人（2002）的模型模拟最优价格上限的结果。价格上限在20世纪80年代成为一种流行的监管工具，比如对电力的监管，尽管导致价格上限监管的动机受到了经济学家的质疑。反事实模拟显示价格上涨，导致消费者剩余显著损失。然而，企业利润的增加并不能抵消这种支持实际收益率机制相关性的损失。
Water utilities are reminiscent of network industries and are characterized by important fixed costs. These factors contribute to a single firm serving an area justifying public intervention on pricing. About one-fourth of U.S. water utilities are private and subject to regulation. Regulators are unlikely to be perfectly informed and regulation is unlikely to be costlessly implemented. These inherent imperfections have led economists to consider the incentive properties of regulatory procedures using the economics of information (see David Baron, 1989). The empirical literature on regulation has focused on evaluating the effects of regulation on prices, firms’ costs, efficiency, and innovation in such sectors as airlines, electricity, and energy, as surveyed by Paul L. Joskow and Nancy L. Rose (1989). Few of these empirical studies rely on the so-called theory of regulation. Regarding the water industry, there is an abundant literature on residential water demand, firms’ cost, and their efficiency, given their public-versusprivate nature. Relying on a model with asymmetric information and a sample of California water utilities, Frank A. Wolak (1994) assesses the consumer welfare loss due to asymmetric information and shows that the model with asymmetric information provides a superior description of the cost and demand data to the model under perfect information. Analyzing pricing for residential water is an important policy issue as the sector recently experienced price increases. The problem is even more acute in California because of a high residential demand for water along with population growth, water scarcity, and the probability of severe droughts. Relying on a new dataset of 32 districts in California over the 1995–2000 period, we analyze regulation of private water utilities. For every district, the California Public Utilities Commission (CPUC) chooses a price for water, an access fee per meter, and a rate of return on capital to satisfy firms’ revenue requirements. We assume that the CPUC is imperfectly informed about firms’ labor efficiency. Following David Besanko (1984) and Wolak (1994), we develop a model in which the firm’s capital is used as a screening variable. In particular, the model has the features of a rate-of-return regulation. We show how the rate of return and the access fee can be determined optimally to control firms’ rents. We then adopt a structural approach to analyze the data. A multistep estimator allows us to estimate the key parameters of the model. The empirical results show price inelasticity, an income effect, slightly decreasing returns to scale, and a concentration of efficient firms. The computation of the optimal rate of return and access fee shows that the CPUC would tend to be cautious by allowing a lower-than-optimal rate and access fee. Relying on the estimated parameters, a first experiment evaluates the cost of asymmetric information. The price would be significantly lower, resulting in a gain of consumer surplus. A second experiment consists of simulating the outcome of an optimal price cap following the Farid Gasmi et al. (2002) model. The price cap became a popular regulatory tool in the 1980s such as for electricity, though the incentives resulting in price cap regulation have been questioned by economists. The counterfactual simulations show a price increase, which results in a significant loss in consumer surplus. The increase in firms’ profit does not, however, counterbalance this loss supporting the relevance of the actual rate-of-return mechanism.