Guillaume Bataille

2024-21

International Fisheries Agreements: Endogenous Exits, Shapley Values, and Moratorium Fishing Policy

Guillaume Bataille, Benteng Zou

Résumé Motivated by recent examples, this study proposes a dynamic multistage optimal control problem to explain the instability of International Fishery Agreements (IFAs). We model two heterogeneous countries that exploit shared fishery resources, and investigate the conditions that lead to a shift from cooperation to competition. We assume that countries differ in their time preferences, initially behave as if the coalition will last indefinitely, use fixed sharing rules during cooperation, and adopt Markovian strategies after withdrawal. Our findings reveal that, for any sharing rule, coalitions of heterogeneous players always break down in finite time. We use the dynamic Shapley Value to decompose the coalition’s aggregate worth over time, thereby eliminating the incentive to leave the agreement. Additionally, we show that a fishing moratorium policy accelerates the recovery of near-extinct fish stocks; however, fishing should resume under a cooperative regime once sustainable levels are achieved.

Mots clés Fisheries, International Fishery Agreements, Dynamic games, Multistage optimal control

Télécharger HAL Google Scholar

2024-05

An Explicit Solution to Harvesting Behaviors in a Predator-Prey System

Guillaume Bataille

Résumé This paper derives closed-form solutions for a strategic, simultaneous harvesting in a predator-prey system. Using a parametric constraint, it establishes the existence and uniqueness of a linear feedback-Nash equilibrium involving two specialized fleets and allow for continuous time results for a class of payoffs that have constant elasticity of the marginal utility. Theses results contribute to the scarce literature on analytically tractable predator-prey models with endogenous harvesting. A discussion based on industry size effects is provided to highlight the role played by biological versus strategic interactions in the multi-species context.

Mots clés Predator-prey relationship, Common-pool resource, Dynamic games, Fisheries

Télécharger HAL Google Scholar

2023-05

The tragedy of the (anti-)commons: The case of prey-predator fisheries

Guillaume Bataille, Hubert Stahn, Agnes Tomini

Résumé We examine the efficiency and environmental consequences of assigning species-specific common-property rights, considering a Lotka-Volterra model in which fisheries are specialized in the harvesting of a single species. We show that the fragmentation of the ecosystem implies the tragedy of the anticommons even when fisheries compete for the resource. Indeed, contrasting the private exploitation equilibrium with the socially optimal solution, we demonstrate that the predator stock is too high while the prey stock is too low under private property rights. A puzzling result is that the "abundant" species is actually underused because of insufficient economic incentives; however, the scarce and high-priced species does not necessarily suffer from overexploitation. Biological interactions are consequently the main driver of stock depletion. Finally, we investigate how to simultaneously solve both the tragedy of the commons and that of the anticommons and analyze the economic costs of regulating only the tragedy of the commons.

Mots clés Exclusive property rights Common-pool resource Anticommons Fisheries, Exclusive property rights, Optimal control, Prey-predator relationship, Fisheries, Anticommons, Common-pool resource

Télécharger HAL Google Scholar