Product review platforms in online marketplaces differ with respect to the granularity of product quality information they provide. While some platforms provide a single overall rating for product quality (also referred to as the single-dimensional rating scheme), others provide a separate rating for each individual quality attribute (also referred to as the multidimensional rating scheme). The multidimensional rating scheme is superior to the single-dimensional rating scheme, ceteris paribus, in reducing consumers’ uncertainty about product quality and value. However, we show that, when sellers respond to product ratings by adjusting their prices, compared to the single-dimensional rating scheme, the multidimensional rating scheme does not always benefit consumers, nor does it necessarily benefit sellers or society. The uncertainty associated with quality attribute rating and the extent of differentiation between competing products determines whether a finer-grained multidimensional rating scheme is superior to a coarser-grained single-dimensional rating scheme from the consumer, seller, and social planner perspectives. The main driver of the results is that more (less) granular and less (more) uncertain information exposes (hides) underlying differentiation, or a lack thereof, between competing products, which, in turn, alters upstream price competition in the presence of heterogeneous consumer preferences. The results demonstrate that focusing on the information transfer aspect of rating schemes provides only a partial understanding of the true impacts of rating schemes.

中文翻译：

---

在线产品评论：细粒度的评级方案是否优于粗粒度的评级方案？

在线市场中的产品评论平台在它们提供的产品质量信息的粒度方面有所不同。虽然一些平台为产品质量提供单一的整体评级（也称为单维评级方案），但其他平台为每个单独的质量属性提供单独的评级（也称为多维评级方案）。在减少消费者对产品质量和价值的不确定性方面，多维评级方案优于单维评级方案（其他条件不变）。然而，我们表明，当卖家通过调整价格来响应产品评级时，与单维评级方案相比，多维评级方案并不总是有利于消费者，也不一定有利于卖家或社会。与质量属性评级相关的不确定性和竞争产品之间的差异程度决定了从消费者、卖家和社会规划者的角度来看，更细粒度的多维评级方案是否优于粗粒度的单维评级方案。结果的主要驱动因素是更多（更少）粒度和更少（更多）不确定性的信息暴露（隐藏）竞争产品之间的潜在差异或缺乏差异，这反过来又改变了存在异质性的上游价格竞争消费者偏好。结果表明，关注评级方案的信息传递方面只能提供对评级方案真正影响的部分理解。