In an extended version of d'Aspremont and Jacquemin's (1988) R&D competition model we find a region where the game is a prisoner's dilemma: firms still invest in R&D but they would obtain a higher profit by not investing at all. In a repeated version of the game, we prove that firms implicitly...

We investigate the issue of strategic substitutability/complementarity in differential games. We prove that instantaneous best replies exist if Hamiltonian functions are multiplicative in the control variables. Otherwise, if the Hamiltonians are addively separable w.r.t. controls, a dominant...

We investigate the issue of strategic substitutability/complementarity in a Cournot differential game with sticky prices. We show that first order conditions do not produce instantaneous best reply functions. However, we identify negatively sloped reaction functions in steady state, with the...

We investigate a linear state differential oligopoly game with advertising, under either Cournot or Bertrand competition. We show that a unique saddlepoint equilibrium exists in both cases if the marginal cost of advertising is sufficiently low. Then, we prove that Bertrand competition entails...

We examine the profitability and social efficiency of horizontal mergers in a Cournot oligopoly with decreasing average costs. Assuming the merger allows for a reduction in the total amount of fixed costs, we identify the conditions under which the merger is, respectively, profitable and...