We develop a model that is a synthesis of the two-sided markets duopoly model of Armstrong (2006) with the nested vertical and horizontal dierentiation model of Gabszewicz and Wauthy (2012), which consists of a linear city with dierent consumer densities on the left and on the right side of the...

We propose a profit-sharing rule that maximizes sustainability of cartel agreements. This rule is such that the critical discount factor is the same for all the firms. If a cartel applies this rule, then asymmetries among firms may not hinder collusion (contrarily to the typical finding in the...

This paper proposes a general framework to study the sustainability of collusion in markets where demand growth (although deterministic) is not restricted to occur at a constant rate and may trigger future entry. It is shown that, typically, entry occurs later along the collusive path than along...

We study competition between two shopping centers (department stores or shopping malls) located at the extremes of a linear city. In contrast with the existing literature, we do not restrict consumers to make all their purchases at a single place. We obtain this condition as an equilibrium...

We study general equilibrium with private and incomplete state verification. Trade is agreed ex ante, that is, before private information is received. It is useful to define a list of bundles as a derivative good that gives an agent the right to receive one of the bundles in the list....

We investigate the continuity of equilibrium in differential information economies with a finite number of agents. In this setting, agents can make contingent contracts based on events that are commonly observed. With private information modelled as finite partitions of a compact and metrizable...

We study regulation of a bureaucratic provider of a public good in the presence of moral hazard and adverse selection. By bureaucratic we mean that it values output in itself, and not only profit. Three different financing systems are studied - cost reimbursement, prospective payment, and the...

We generalize the model of Krugman (1991) to allow for asymmetric trade costs between regions and for (asymmetric) trade costs that are internal to the regions. We find that industrial activity, in a region, is enhanced by higher costs of importing and lower costs of exporting (more precisely,...

We give an illustration of hysteresis (path-dependence) in a simple economy. In the presence of multiple possible equilibrium prices, we find that past expectations determine present prices. This phenomenon of path-dependence is robust under perturbations of the economy.

An example is given in which agents agree to disagree, showing that Aumann's (1976) Agreement Theorem does not extend to a countable space of equiprobable states of nature. Even in this unorthodox setting, if the sets of the information partitions are intervals, an agreement theorem holds. A...