This paper examines retail grocery price levels with a very large (unbalanced) panel of stores that operate in well-defined local markets. We explain price variation across grocery retailers by the concentration of wholesalers and retailers, and the market share of hypermarkets (and control for...

For many products, platforms enable sellers to transact with buyers. We show that the competitive conditions among sellers shape the market structure in platform industries. If product market competition is tough, sellers avoid competitors by joining different platforms. This allows platforms to...

This paper analyses a two-sided market in which two platforms compete against each other. One side, the advertisers, exerts a negative externality on the ther side, the users. It is shown that if platforms can charge advertisers only, a higher degree of competition for users can lead to higher...