We analyse optimal penal codes in both Bertrand and Cournot supergames with product differentiation. We prove that the relationship between optimal punishments and the security level (individually rational discounted profit stream) depends critically on the degree of supermodularity in the stage...

This paper investigates the endogenous choice between price- and quantity-setting behaviour in a duopoly game where firms invest in product development first, and then play a marketing game later. Only in the initial R&D stage, the two firms set up a joint venture in order to share the costs of...

We characterize the interplay between firm's decisions in product development, be it joint or independent, and their ensuing repeated price behaviour, either collusive or Bertrand-Nash. We prove that joint-product development and the resulting lack of horizontal differentiation may destabilise...

In an oligopoly supergame, firms' actions in prices and quantities are subject to non-negativity constraints. These constraints can obstruct the practicability of optimal punishment (a la Abreu (1986), Lambson (1987), and Hackner (1996)) in sustaining tacit collusion. Noting that the prospect of...

In an oligopoly supergame, firms face an obvious technological constraint: the positivity of their production quantities. WE show that Lambson's (1987) result on "security-level punishment", that the single-period punishment makes the firm's discounted participation condition just bind, holds...