Collaborative Research: Dynamic Demand for New Durable Goods: An Empirical Model and Applications to Pricing and Welfare

在许多行业，消费者不仅选择购买什么，而且选择何时购买。 然而，经济学家缺乏令人信服的模型，总需求的情况下，许多论文指定静态模型的行业，显然具有动态特征。 为了解决这个问题，本研究扩展了以前的几条研究路线，指定和估计的第一个动态随机系数模型的消费者需求的总数据。 这项研究使用这种方法来分析两个可见的消费电子行业，数码相机和DVD播放器的研究很少的数据集。 本研究的主要目的是发展新的方法来估计消费者需求的动态与总的数据。使用这些方法，这项工作的研究在这些行业中的几个重要的应用问题。 特别是，这项研究旨在评估为什么这些行业的价格如此急剧下降，这是许多新耐用品市场的普遍特征。 虽然跨期价格歧视、进入和成本下降的典型解释早已得到承认，但以前的工作没有对它们的相对重要性提供经验评估。 本研究还调查了这些行业的福利和价格指数。 当消费者可能推迟购买时，标准价格指数就有问题，因为指数不能处理数量随时间推移而扩大的情况，或者消费者利用当前价格变化来预测最佳购买时间的情况。 这些功能自然占在拟议的模型，预计将是重要的数据集正在审议。 因此，本研究的另一个贡献是，它提供了答案，这些问题的基础上，理论和经验连贯的模型。 首先，一个新的方法来估计消费者的需求。 作者将在万维网上分发用于实施该方法的计算机代码和算法。 所提出的方法可以被其他研究人员广泛用于其他行业。 其次，研究结果可能对政策制定者产生重要的更广泛的影响。 例如，科斯猜想表明，如果消费者知道未来价格将会下降，那么垄断者即使受到进入壁垒的保护，也可能几乎没有市场支配力。 对这一问题的实证分析对于竞争主管机构的合并分析和其他问题可能很重要。 关于如何评估价格指数的研究对创建这些指数的政府机构非常感兴趣，这些指数以多种方式影响经济。

In many industries, consumers choose not only what to purchase but when to purchase. However, economists lack compelling models of aggregate demand for this case and many papers specify static models in industries that clearly have dynamic features. In order to address this problem, this study extends several previous lines of research to specify and estimate the first dynamic random coefficients model of consumer demand designed for aggregate data. This study uses this method to analyze little-studied data sets on two visible consumer electronics industries, digital cameras and DVD players. The principal focus of this study is to develop new methods to estimate the dynamics of consumer demand with aggregate data.Using these methods, this work studies several important applied questions in these industries. In particular, this research seeks to evaluate why prices fall so dramatically in these industries, a ubiquitous feature of many new durable goods markets. While the typical explanations of intertemporal price discrimination, entry and cost declines have long been recognized, no previous work has provided an empirical evaluation of their relative importance. This study also investigates welfare and price indices in these industries. Standard price indices are problematic when consumers can delay purchase because indices do not handle situations in which quantity expands over time or when consumers use current price changes to predict the optimal purchase time. These features are naturally accounted for in the proposed model and are expected to be important in the data sets under consideration. Thus, another contribution of this study is that it provides answers to these questions, based on theoretically and empirically coherent models.There are two important broader implications of this study. First, a new methodology for estimating consumer demand is developed. Computer code and algorithms for implementing the methodology will be distributed on the World Wide Web by the authors. The proposed methods can be widely used by other researchers for other industries. Second, the results could have important broader implications for policy makers. For instance, the Coase conjecture suggests that if consumers know prices will fall in the future, a monopolist may have little market power even if it is protected by barriers to entry. Empirical analysis of this issue could be important for merger analysis and other questions faced by a competition authority. Research about how to evaluate price indices are of significant interest to government agencies that create these indices, and these indices impact the economy in a large variety of ways.