Knowledge that Transforms

We propose a structural model to study the effect of online product reviews on consumer purchases of experiential products. Such purchases are characterized by limited repeat purchase behavior of the same product item (such as a book title) but significant past usage experience with other products of the same type (such as books of the same genre). To cope with the uncertainty in quality of the product item, we posit that consumers may learn from their experience with the same type of product and others' experiences with the product item. We model the review credibility as the precision with which product reviews reflect the consumer's own product evaluation. The higher the precision, the more credible the information obtained from product reviews for the consumer, and the larger the effect of reviews on the consumer's choice probabilities. We extend the Bayesian learning framework to model consumer learning on both product quality and review credibility. We apply the model to a panel data set of 1,919 book purchases by 243 consumers. We find that consumers learn more from online reviews of book titles than from their own experience with other books of the same genre. In the counterfactual analysis, we illustrate the profit impact of product reviews and how it varies with the number of reviews. We also study the phenomenon of fake reviews. We find that fake reviews increase consumer uncertainty. The effects of more positive reviews and more numerous reviews on consumer choice are smaller on online retailing platforms that have fake product reviews.

A firm may want to preannounce its plans to develop a new product in order to stimulate future demand. But given that such communications can affect rivals' incentives to develop the same new product, a firm may decide to preannounce untruthfully in order to deter competitors. We examine an incumbent's preannouncement strategy when there is uncertainty regarding the commercial viability of a new product opportunity and a threat of rival entry. Each firm has a private assessment of the market potential for the new product. Two competitive incentives arise for the incumbent in terms of discouraging rival entry: it can use preemptive communication or it can remain silent and instill a pessimistic market potential outlook. We find that an incumbent prefers to follow a vaporware strategy—i.e., declares plans to pursue a new product opportunity even when it may have no development intentions—when its market forecasting capabilities are weak and the demand-side benefits from preannouncing are small. By contrast, when the incumbent has strong market forecasting capabilities and the demand-side benefits are small, the incumbent adopts a suddenware strategy—i.e., remains silent about its new product plans even when it actually plans to develop the new product. Finally, when its market forecasting capabilities are strong and the demand-side benefits are large, the incumbent prefers to engage in a trueware strategy—i.e., truthfully preannounces development plans. We show that an interplay between competition-related and demand-related considerations is what allows trueware to emerge as an equilibrium in the absence of any ex post cost to engaging in vaporware. In an extension, we let the incumbent's actual development plans leak out and allow the entrant to wait and learn those plans prior to setting a research and development level. We identify conditions for the entrant to postpone development despite the risk of being late to market, as well as conditions for the entrant to commence development immediately despite not knowing the incumbent's plans based on the observed preannouncement strategy.

I consider a cheap-talk model in which a firm has a chance to communicate its product quality to consumers. The model describes how advertising can be both informative to consumers and profitable for the firm through its content in a vertically differentiated market. I find that advertising content may be effective in inducing search even if incentives for misrepresentation exist. In particular, a firm with an undesirable (low-quality) product is able to attract consumers who would have not incurred a search cost had they known its true quality. In this case, a semiseparating equilibrium occurs where the lowest firm types pool upward in order to increase the expected product quality while simultaneously signaling that the product is affordable. Although consumers always benefit from truth in advertising, total welfare may decrease if an undesirable firm is required to reveal its type. Finally, I show that the extent to which misrepresentation can take place increases with the cost of advertising coverage.

This paper examines the impact of search engine optimization (SEO) on the competition between advertisers for organic and sponsored search results. The results show that a positive level of search engine optimization may improve the search engine's ranking quality and thus the satisfaction of its visitors. In the absence of sponsored links, the organic ranking is improved by SEO if and only if the quality provided by a website is sufficiently positively correlated with its valuation for consumers. In the presence of sponsored links, the results are accentuated and hold regardless of the correlation. When sponsored links serve as a second chance to acquire clicks from the search engine, low-quality websites have a reduced incentive to invest in SEO, giving an advantage to their high-quality counterparts. As a result of the high expected quality on the organic side, consumers begin their search with an organic click. Although SEO can improve consumer welfare and the payoff of high-quality sites, we find that the search engine's revenues are typically lower when advertisers spend more on SEO and thus less on sponsored links. Modeling the impact of the minimum bid set by the search engine reveals an inverse U-shaped relationship between the minimum bid and search engine profits, suggesting an optimal minimum bid that is decreasing in the level of SEO activity.