On the Environmental Efficiency of Water Storage: The Case of a Conjunctive Use of Ground and Rainwater

Rainwater harvesting, consisting in collecting runoff from precipitation, has been widely developed to stop groundwater declines and even raise water tables. However this expected environmental effect is not self-evident. We show in a simple setting that the success of this conjunctive use depends on whether the runoff rate is above a threshold value. Moreover, the bigger the storage capacity, the higher the runoff rate must be to obtain an environmentally efficient system. We also extend the model to include other hydrological parameters and ecological damages, which respectively increase and decrease the environmental efficiency of rainwater harvesting

Is the Gisser and Sanchez model too simple to discuss the economic relevance of groundwater management?

ACLNInternational audienceThis paper discusses the framing of the model of Gisser and Sánchez (1980) [9] which is commonly reproduced by the follow-up literature. We note that results on the magnitude of welfare gains from optimal groundwater management are affected by the models׳ limitations, such as the commonly used assumption on the linear relationship between pumping cost and the water table level, and the absence of considerations for non-consumptive benefits. We question the appropriateness of these assumptions since the stock effect (the dependence of extraction cost and/or that of benefits on the stock of resource) affects the time variation of the shadow price. We demonstrate that this leads to a declining value of in situ resource over time. As such, its addition on marginal extraction cost may be negligible, and consequently favors the validation of the Gisser-Sánchez effect

Externality and common-pool resources: The case of artesian aquifers

International audienceThis study examines a specific class of common-pool resources whereby rivalry is not characterized by competition for the resource stock. Artesian aquifers are a typical example of such resources since the stock never depletes, even when part of the resource is extracted. We first propose a dynamic model to account for the relevant features of such aquifers such as the water pressure and well yield and characterize the corresponding dynamics. We then compare the social optimum with the private exploitation of an open-access aquifer. The comparison of these two equilibria highlights the existence of a new source of inefficiency. In the long run, this so-called pressure externality results in an additional number of wells for the same water consumption, thereby raising costs. Finally, we characterize a specific stock-dependent tax to neutralize the pressure externality

Marine ecosystem considerations and second-best management

We compare how the long-run distribution of fishing activities is affected in multispecies fisheries when facing different second-best control rules: (1) species-specific landing regulation, and (2) global input regulation. We show how this depends on the economic returns and on the type of ecological interaction considered. We highlight specifically that fishing effort does not necessarily increase on nontargeted species and decrease on targeted species, and that the characterization of second-best efficient instruments may differ drastically depending on the nature of the interaction

On the Environmental Efficiency of Water Storage: the Case of a Conjunctive use of Ground and Rainwater

ACL-2International audienceRainwater harvesting, consisting in collecting runoff from precipitation, has been widely developed to stop groundwater declines and even raise water tables. However, this expected environmental effect is not self-evident. We show in a simple setting that the success of this conjunctive use depends on whether the runoff rate is above a threshold value. Moreover, the bigger the storage capacity, the higher the runoff rate must be to obtain an environmentally efficient system. We also extend the model to include other hydrological parameters and ecological damages, which respectively increase and decrease the environmental efficiency of rainwater harvesting

Limited tenure concessions for collective goods

International audienceThis paper proposes and analyzes the consequences of a widely-used, but little-studied institution, limited-tenure concessions, for governing club goods and common-pool resources. We first show in a simple repeated game setting that such a system can incentivize socially-efficient provision of club goods. We then extend the model to account for spatially-connected resources, an arbitrary number of heterogeneous agents, and natural resource dynamics, and show that the basic ability of limited-tenure concessions to incentivize the first best private provision is preserved in this rich setting that is more representative of natural resources such as fish, water, and game. The duration of tenure and the dispersal of the resource then play pivotal roles in whether this limited-duration concession achieves the socially optimal outcome. Finally, in a setting with costly monitoring, we discuss the features of a concession contract that ensure first-best behavior, but at least cost to the implementing agency

Limited-tenure concessions for collective goods

International audienceWe analyze theoretically an institution called a “limited-tenure concession” for its ability to induce efficient public goods contribution and common-pool resource extraction. The basic idea is that by limiting the tenure over which an agent can enjoy the public good, but offering the possibility of renewal contingent on ample private provision of that good, efficient provision may be induced. We first show in a simple repeated game setting that limited-tenure concessions can incentivize socially-efficient provision of public goods. We then analyze the ability of this instrument to incentivize the first best provision for common-pool natural resources such as fish and water, thus accounting for spatial connectivity and growth dynamics of the resource. The duration of tenure and the dispersal of the resource play pivotal roles in whether this limitedtenure concession induces the socially optimal private provision. Finally, in a setting with costly monitoring, we discuss the features of a concession contract that ensure first-best behavior, but at least cost to the implementing agency

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

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

Limited tenure concessions for collective goods

International audienceThis paper proposes and analyzes the consequences of a widely-used, but little-studied institution, limited-tenure concessions, for governing club goods and common-pool resources. We first show in a simple repeated game setting that such a system can incentivize socially-efficient provision of club goods. We then extend the model to account for spatially-connected resources, an arbitrary number of heterogeneous agents, and natural resource dynamics, and show that the basic ability of limited-tenure concessions to incentivize the first best private provision is preserved in this rich setting that is more representative of natural resources such as fish, water, and game. The duration of tenure and the dispersal of the resource then play pivotal roles in whether this limited-duration concession achieves the socially optimal outcome. Finally, in a setting with costly monitoring, we discuss the features of a concession contract that ensure first-best behavior, but at least cost to the implementing agency