Ranking have become increasingly popular on markets for study programs, restaurants, wines, cars, etc. This paper analyses the welfare implication of such rankings. Consumers have to make a choice between two goods of unknown quality with exogenous presence or absence of an informative ranking....

After some decades of relative oblivion, the interest in the optimality properties of monopolistic competition has recently re-emerged due to the availability of an appropriate and parsimonious framework to deal with firm heterogeneity. Within this framework we show that non-separable utility,...

We describe a model of fundraising in social groups, where private information about quality of provision is transmitted by social proximity. Individuals engage in voluntary provision of a pure collective good that is consumed by both neighbors and non-neighbors. We show that, unlike in the case...

We study competition between nonprofit providers supplying a collective service through increasing-returns-to-scale technologies. When providers adopt a not-for-profit mission, the absence of a residual claimant can impede entry, pro- tecting the position of an inefficient incumbent. Moreover,...

We study contestability in non-profit markets where non-commercial providers supply a homogeneous collective good or service through increasing-returns-to-scale technologies. Unlike in the case of for-profit markets, in the non-profit case the absence of price-based sales contracts between...

This paper examines how the introduction of a direct trade alternative for buyers and sellers affects competition among middlemen. Direct trade makes middlemen’s supply and demand functions depend on both bid and ask prices, a feature we term interdependence. A simple model is used to...

The paper provides policymakers and regulators with an overview of the more relevant theoretical issues related to the pricing of access to ensure that the political debate around practical concerns is solidly grounded. The paper discusses in detail the importance of access pricing in the...

We consider a pure exchange economy, where for each good several trading institutions are available, only one of which is market-clearing. The other feasible trading institutions lead to rationing. To learn on which trading institutions to coordinate, traders follow behavioural rules of thumb...

A number of empirical studies document that marginal cost shocks are not fully passed through to prices at the firm level and that prices are substantially less volatile than costs. We show that in the relative-deep-habits model of Ravn, Schmitt-Grohé, and Uribe (2006), firm-specific marginal...

This paper analyses a situation where market designers create new trading platforms and traders learn to select among them. We ask whether 'Walrasian' platforms, leading to market-clearing trading outcomes, will dominate the market in the long run. If several market designers are competing, we...