We analyse the problem of the choice of the market variable in a model where firms activate R&D investments for process innovation. We establish that (i) firms always choose the Cournot behaviour; and (ii) there exists a set of the relevant parameters where a benevolent social planner prefers...

We analyse R&D activity in transport and communication technology (TCRD), in a Cournot duopoly. Transport and communication costs are of the iceberg type, i.e., using up some portion of the product along its path to the final buyer. Firms invest in TCRD to increase the net amount of the product...

In this paper we propose a simple, intuitive approach to asset valuation in terms of marginal contributions to the characteristics (moments) of the market portfolio. Considering only the first two moments, mean and variance, the valuation equation is shown to correspond to Sharpe's CAPM. A...

We investigate a dynamic Cournot duopoly with intraindustry trade, where firms invest in R&D to reduce the level of iceberg transportation costs. We adopt both open-loop and closed-loop equilibrium concepts, showing that a unique (saddle point) steady state exists in both cases. In the open-loop...

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 timing of adoption of product and process innovation by using a differential game in which firms may invest in both activities. We consider horizontal product innovation that reduces product substitutability, and process innovation that reduces marginal cost. First, we...

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 model the optimal behaviour of a multiproduct monopolist investing both in process and in product innovation in a dynamic setting. Product innovation reduces the degree of substitutability between any two varieties. First, we find that R&D efforts increase in both directions as the number of...

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...