A new mechanism for product tests à la Consumer Reports, Stiftung Warentest and Co. – Adopting a long-term perspective with endogenous price and quality, and unknown distribution of quality

卖方往往比买方更了解产品质量。为了减少这种信息不对称并帮助购买者，已经建立了产品测试组织，如消费者报告（美国）或Stiftung Warentest（德国）。虽然它们提供了可靠的信息，但这些信息可能不是最佳的。由于测试能力有限，必须选择某些产品型号（例如所有可用型号中的某些智能手机型号）进行测试。例如，Stiftung Warentest主要选择最畅销的产品型号，认为买家最感兴趣的是了解畅销产品的质量。然而，可能有产品模型之间的未测试的占主导地位的测试产品模型（例如，在相同的质量是较便宜的）。我们提出了一个新的，能力中立的机制来选择产品模型的测试。我们的机制允许卖家向产品测试机构申请产品型号，说明价格和质量。然后，产品检测机构根据预先指定的算法在申请者中选择待检测的产品型号，允许卖家自愿披露其产品质量。在一项初步的实验研究（Vollstädt，Brendel，Ehses-Friedrich，油印）中，我们比较了两种基准处理：Stiftung Warentest当前机制的程式化版本和我们的新机制。我们表明，我们的机制会导致产品测试包含有关非主导产品模型的更多信息。因此，消费者剩余以及某些卖家的利润增加。虽然这些初步结果是非常有希望的，他们依赖于几个强有力的假设。本研究建议的目标是通过放松两个主要假设来逐渐增加我们结果的外部有效性。在项目1中，我计划放松价格和质量是外生的假设。为了实现这一点，我将扩展的静态，短期的游戏中使用的初步研究，一个动态的，长期的游戏中，价格和质量是内生的。我们的新机制，即使是内生的价格和质量，是否会比华伦泰基金会机制的程式化版本表现得更好？此外，我们的新机制会否带来更好的产品型号（例如，在相同品质的情况下，较便宜的产品型号）？在项目2中，我计划放松买方和卖方知道产品质量如何分布的假设。这一假设在所有关于自愿性信息披露的相关研究中都是成立的，在我们的初步研究中也是如此。然而，这一假设实际上既不适用于大多数买家，也不适用于所有卖家。即使产品质量的分布是未知的，我们的新机制是否会比Stiftung Warentest机制的程式化版本表现得更好？

Sellers are often better informed about product quality than buyers. To reduce this asymmetric information and to help buyers, product testing organizations like Consumer Reports (US) or Stiftung Warentest (Germany) have been established. Although they provide credible information, this information may not be optimal. Due to limited testing capacities, certain product models (e.g. certain smartphone modells among all available ones) have to be selected for a test. For instance, Stiftung Warentest selects mainly the bestselling product models, arguing that buyers would be interested most in learning about the bestsellers' quality. However, there may be product models among the non-tested ones which dominate the tested product models (e.g. are less expensive given the same quality).We propose a new, capacity-neutral mechanism to select product models for a test. Our mechanism allows sellers to apply to the product testing organization with a product model, stating price and quality. The product testing organization then selects the product models to be tested among the applicants according to a pre-specified algorithm, allowing sellers to voluntarily disclose their product quality. In a preliminary experimental study (Vollstädt, Brendel, Ehses-Friedrich, mimeo), we compared two benchmark treaments: a stylized version of Stiftung Warentest’s current mechanism and our new mechanism. We showed that our mechanism leads to product tests with more information on non-dominated product models. Therefore, consumer surplus as well as profits of certain sellers increase.While these preliminary results are very promising, they rely on several strong assumptions. The goal of the present research proposal is to gradually increase the external validity of our results by relaxing two major assumptions. In project 1, I plan to relax the assumption that price and quality are exogenous. To achieve this, I will extend the static, short-term game used in the preliminary study to a dynamic, long-term game in which price and quality are endogenous. Will our new mechanism, even with endogenous price and quality, perform better than a stylized version of Stiftung Warentest’s mechanism? Moreover, will our new mechanism lead to a supply of better product models (e.g. less expensive product models given the same quality)? In project 2, I plan to relax the assumption that buyers and sellers know how product quality is distributed. This assumption is made in all related studies on voluntary information disclosure and also in our preliminary study. Yet, this assumption does actually neither hold for most buyers, nor for all sellers. Will our new mechanism perform better than a stylized version of Stiftung Warentest’s mechanism even if the distribution of product quality is unknown?