Long-term contracting in hydro-thermal electricity generation: welfare and environmental impact

We consider electricity generation industries where thermal operators imperfectly compete with hydro operators that manage a (scarce) water stock stored in reservoirs over a natural cycle. We explore how the exercise of intertemporal market power affects social welfare and environmental quality. We show that, as compared to the outcome of spot markets, long-term contracting either exacerbates or alleviates price distortions, depending upon the consumption pattern over the water cycle. Moreover, it induces a second-order environmental effect that, in the presence of a thermal competitive fringe, is critically related to the thermal market shares in the different periods of the cycle. We conclude by providing policy insights.

On the Timing of Vertical Relationships

We show that the standard analysis of vertical relationships transposes directly to investment timing. Thus, when a firm undertaking a project requires an outside supplier (e.g. an equipment manufacturer) to provide it with a discrete input, and if the supplier has market power, investment occurs too late from an industry standpoint. The distortion in firm decisions is characterized by a Lerner index, which is related to the parameters of a stochastic downstream demand. When feasible, vertical restraints restore efficiency. For instance, the upstream firm can induce entry at the correct investment threshold by selling a call option on the input. Otherwise, competition may substitute for vertical restraints. In particular, if two firms are engaged in a preemption race downstream, the upstream firm sells the input to the first investor at a discount that is chosen in such a way that the race to preempt exactly offsets the vertical externality, and this leader invests at the optimal market threshold.

Sharing the Cost of Global Warming

Due to meteorological factors, the distribution of the environmental damage due to climate change bears no relationship to that of global emissions. We argue in favor of offsetting this discrepancy, and propose a “global insurance scheme” to be financed according to countries’ responsibility for climate change. Because GHG decay very slowly, we argue that the actual burden of global warming should be shared on the basis of cumulated emissions, rather than sharing the expected costs of actual emissions as in a Pigovian taxation scheme. We characterize new versions of two well-known cost-sharing schemes by adapting the responsibility theory of Bossert and Fleurbaey (1996) to a context with externalities.Climate Change, Cost Sharing, Responsibility, Compensation

Optimal Collusion with Limited Liability and Policy Implications

Collusion sustainability depends on firms’ aptitude to impose sufficiently severe punishments in case of deviation from the collusive rule. We characterize the ability of oligopolistic firms to implement a collusive strategy when their ability to punish deviations over one or several periods is limited by a severity constraint. It captures all situations in which either structural conditions (the form of payoff functions), institutional circumstances (a regulation), or financial considerations (profitability requirements) set a lower bound to firms’ losses. The model specifications encompass the structural assumptions (A1-A3) in Abreu (1986) [Journal of Economic Theory, 39, 191-225]. The optimal punishment scheme is characterized, and the expression of the lowest discount factor for which collusion can be sustained is computed, that both depend on the status of the severity constraint. This extends received results from the literature to a large class of models that include a severity constraint, and uncovers the role of structural parameters that facilitate collusion by relaxing the constraint.