In markets with quality unobservable to buyers, third-party certification is often the only instrument to increase transparency. While both sellers and buyers have a demand for certification, its role differs fundamentally: sellers use it for signaling, buyers use it for inspection. Seller...

This paper considers a market in which only the incumbent's quality is publicly known. The entrant's quality is observed by the incumbent and some fraction of informed consumers. This leads to price signalling rivalry between the duopolists, because the incumbent gains and the entrant loses when...

This paper analyzes optimal product lines when consumers differ both in their taste for quality and in their desire for social image. The market outcome features partial pooling and product differentiation that is not driven by heterogeneous valuations for quality but by image concerns. A...

Products produced by a multiproduct firm can be linked through demand linkages or supply linkages. On the demand side, changes in the price of one product can affect the demand for a firm's other products through shifts in consumer expenditures. This is commonly referred to as the...

Platforms often display their products ahead of third-party products in search. Is this due to consumers preferring platform-owned products or platforms engaging in self-preferencing by biasing search towards their own products? What are the welfare implications? I develop a structural model of...

This paper examines the publication of quality indicators in service markets with public finance systems, such as education and healthcare markets. We provide a spatial model of product differentiation in which the reporting of such indicators increases consumers’ decision weight on quality...

Review systems including quantitative measures as well as text-based expression of experiences are omnipresent in today’s digital platform economy. This paper studies the existence of reputation inflation, i.e. unjustified increases in ratings, with a special focus of heterogeneity between...

I study a cheap talk model between a buyer and a seller with two goods for sale. There is two-sided (independent) private information with sequential, two-way communication. In the first stage, the buyer communicates her private preferences to the seller. In the second stage, the seller...

This paper shows that the possibility of collusion between an agent and a supervisor imposes no restrictions on the set of implementable social choice functions (SCF) and associated payoff vectors. Any SCF and any payoff profile that are implementable if the supervisor's information was public...