Market Power, Resource Extraction and Pollution: Some Paradoxes and a Unified View

We adopt a stepwise approach to the analysis of a dynamic oligopoly game in which production makes use of a natural resource and pollutes the environment, starting with simple models where firms' output is not a function of the natural resource to end up with a full-fledged model in which (i) the resource is explicitly considered as an input of production and (ii) the natural resource and pollution interact via the respective state equations. This allows us to show that the relationship between the welfare properties of the economic system and the intensity of competition is sensitive to the degree of accuracy with which the model is constructed

On the attainment of the maximum sustainable yield in the Verhulst-Lotka-Volterra model

We reformulate the Verhulst-Lotka-Volterra model of natural resource extraction under the alternative assumptions of Cournot behaviour and perfect competition, to revisit the tragedy of commons vs the possibility of sustainable harvesting. We stress the different impact of demand elasticity on the regulator’s possibility of driving industry harvest to the maximum sustainable yield in the two settings. The presence of a flat demand function offers the authority a fully effective regulatory tool in the form of the exogeneous price faced by perfectly competitive firms, to drive their collective harvest rate at the maximum sustainable yield. The same cannot happen under Cournot competition, as in this case the price is endogenous and the regulator’s policy is confined to limiting access to the common pool

Perfect uncontrollable differential games

This paper analyses the time consistency of open-loop equilibria, in the cases of Nash and Stackelberg behaviour. We define a class of games where the strong time-consistency of the open-loop Nash equilibrium associates with the time consistency of the open-loop Stackelberg equilibrium. We label these games as ‘perfect uncontrollable’. We provide one example based on a model of oligopolistic competition in advertising efforts. We also present two oligopoly games where one property holds while the other does not, so that either (i) the open-loop Nash equilibrium is subgame perfect while the stackelberg one is time inconsistent, or (ii) the open-loop Nash and Stackelberg equilibria are only weakly time consistent

Degenerate feedback and time consistency in dynamic games

This paper analyses the time consistency of open-loop equilibria, in the cases of Nash and Stackelberg behaviour. We define a class of games where the strong time-consistency of the open-loop Nash equilibrium associates with the time consistency of the open-loop Stackelberg equilibrium. We label these games as `perfect uncontrollable' and provide two examples based on (i) a model where firms invest so as to increase consumers' reservation prices, based upon Cellini and Lambertini (CEJOR, 2003); and (ii) a model where firms compete to increase their respective market shares, based upon Leit- mann and Schmitendorf (IEEE Transactions on Automatic Control, 1978)

Hamiltonian potential functions for differential games

We introduce the concept of Hamiltonian potential function for noncooperative open-loop differential games with n players, n controls and n states, and characterise a sufficient condition for its existence. We also identify a class of games admitting a Hamiltonian potential and provide appropriate examples pertaining to advertising, industrial organization and macroeconomic policy

A Stochastic Optimal Control Model of Pollution Abatement

We model a dynamic monopoly with environmental externalities,investigating the adoption of a tax levied on the firm's instantaneous contribution to the accumulation of pollution. The latter process is subject to a shock, which is i.i.d. across instants. We prove the existence of an optimal tax rate such that the monopoly replicates the same steady state welfare level as under social planning. Yet, the corresponding output level, R&D investment for environmental friendly technologies and surplus distribution necessarily differ from the socially optimal ones

R&D for green technologies in a dynamic oligopoly: Schumpeter, Arrow and inverted-U’s

We extend a well known differential oligopoly game to encompass the possibility for production to generate a negative environmental externality, regulated through Pigouvian taxation and price caps. We show that, if the price cap is set so as to fix the tolerable maximum amount of emissions, the resulting equilibrium investment in green R&D is indeed concave in the structure of the industry. Our analysis appears to indicate that inverted-U-shaped investment curves are generated by regulatory measures instead of being a "natural" feature of firms’ decisions