A Hydraulic Approach to Equilibria of Resource Selection Games

Drawing intuition from a (physical) hydraulic system, we present a novel framework, constructively showing the existence of a strong Nash equilibrium in resource selection games (i.e., asymmetric singleton congestion games) with nonatomic players, the coincidence of strong equilibria and Nash equilibria in such games, and the uniqueness of the cost of each given resource across all Nash equilibria. Our proofs allow for explicit calculation of Nash equilibrium and for explicit and direct calculation of the resulting (unique) costs of resources, and do not hinge on any fixed-point theorem, on the Minimax theorem or any equivalent result, on linear programming, or on the existence of a potential (though our analysis does provide powerful insights into the potential, via a natural concrete physical interpretation). A generalization of resource selection games, called resource selection games with I.D.-dependent weighting, is defined, and the results are extended to this family, showing the existence of strong equilibria, and showing that while resource costs are no longer unique across Nash equilibria in games of this family, they are nonetheless unique across all strong Nash equilibria, drawing a novel fundamental connection between group deviation and I.D.-congestion. A natural application of the resulting machinery to a large class of constraint-satisfaction problems is also described.Comment: Hebrew University of Jerusalem Center for the Study of Rationality discussion paper 67

5 minutes with Yannai A. Gonczarowski

We were pleased to have Yannai. A. Gonczarowski (Hebrew University of Jerusalem and Microsoft Research) visit our Department recently. During his time with us, he not only gave his excellent seminar on “Cascading to Equilibrium: Hydraulic Computation of Equilibria in Resource Selection Games“, but also generously gave his time to answer a short Q & A, covering everything from resource selection games, to creative thinking in mathematics, to finding the time to perform opera

Optimal Mechanisms for Heterogeneous Multi-cell Aquifers

Standard economic models of groundwater management impose restrictive assumptions regarding perfect transmissivity (i.e., the aquifer behaves as a bathtub), no external effects of groundwater stocks, observability of individual extraction rates, and/or homogenous agents. In this article, we derive regulatory mechanisms for inducing the socially optimal extraction path in Markov perfect equilibrium for aquifers in which these assumptions do not hold. In spite of the complexity of the underlying system, we identify an interesting case in which a simple linear mechanism achieves the social optimum. To illustrate potential problems that can arise by erroneously imposing simplifying assumptions, we conduct a simulation based on data from the Indian state of Andhra Pradesh.Common Property Resource, Differential Games, Groundwater Extraction, Imperfect Monitoring, Markov Perfect Equilibrium

Monotonicity of equilibria in nonatomic congestion games

This paper studies the monotonicity of equilibrium costs and equilibrium loads in nonatomic congestion games, in response to variations of the demands. The main goal is to identify conditions under which a paradoxical non-monotone behavior can be excluded. In contrast with routing games with a single commodity, where the network topology is the sole determinant factor for monotonicity, for general congestion games with multiple commodities the structure of the strategy sets plays a crucial role. We frame our study in the general setting of congestion games, with a special focus on singleton congestion games, for which we establish the monotonicity of equilibrium loads with respect to every demand. We then provide conditions for comonotonicity of the equilibrium loads, i.e.,we investigate when they jointly increase or decrease after variations of the demands. We finally extend our study from singleton congestion games to the larger class of constrained series-parallel congestion games, whose structure is reminiscent of the concept of a series-parallel network

Alternative water management scenarios for Saudi Arabia

Natural Resources;environmental economics

Water Infrastructures Facing Sustainable Development Challenges: Integrated Evaluation of Impacts of Dams on Regional Development in Morocco

During the past century, large hydraulic infrastructures have been considered as the most effective tools for increasing water supply and rationalise water management. According to this approach, large infrastructures are seen as catalysts for territorial development and economic progress. More recently, international surveys of results of water supply policies and performances of large dams, show that these structures need to be integrated in more comprehensive Integrated Water Resource Management strategies at catchments’ scale, to promote equitable and sustainable regional development. The aim of this communication is to present the role of large hydraulic infrastructures within the regional development dynamics with particular attention to the Sebou basin in Morocco, in order to assess some relevant impacts on local communities and their ecosystems. The Sebou region is one of the most important basins in Morocco, in the context of the national strategies and policies of management of water resources, established by the Water Law of 1995. The development of hydraulic infrastructures in the Sebou Basin begun in 1935, with construction of a complex of ten large dams and nine small dams, to provide water for agriculture, domestic and industrial use, and to generate hydropower and control floods, in line with the national water policies that, from the 1960s onwards, looked at large dams as core infrastructures for regional development. A critical view will be given about the coherence of this strategy with the sustainability principles.Water Policy, Morocco, Dams, Sustainable Development, Impacts

An Integrated Assessment Framework for Water Resources Management: A DSS Tool and a Pilot Study Application

Decision making for the management of water resources is a complex and difficult task. This is due to the complex socio-economic system that involves a large number of interest groups pursuing multiple and conflicting objectives, within an often intricate legislative framework. Several Decision Support Systems have been developed but very few have indeed proved to be effective and truly operational. MULINO (Multisectoral, Integrated and Operational Decision Support System for Sustainable Use of Water Resources at the Catchment Scale) is a project funded under the Fifth Framework Programme of the European Research and the key action line dedicated to operational management schemes and decision support system for sustainable use of water resources. The MULINO DSS (mDSS) integrates hydrological models with multi-criteria decision methods and adopts the DPSIR (Driving Force – Pressure – State – Impact – Response) framework developed by the European Environment Agency. The DPSIR was converted from a static reporting scheme into a dynamic framework for integrated assessment modelling (IAM) and multi-criteria evaluation procedures. This paper presents the methodological framework and the intermediate results of the mDSS tool through its application in a pilot study area located in the Watershed of the Lagoon of Venice.Integrated water resources management, Spatial decision-making, Decision support system, Catchment, Environmental modelling

Dynamic Traffic Models in Transportation Science

Traffic assignment models are crucial for traffic planners to be able to predict traffic distributions, especially, in light of possible changes of the infrastructure, e.g., road constructions, traffic light controls, etc. The starting point of the seminar was the observation that there is a trend in the transportation community (science as well as industry) to base such predictions on complex computer-based simulations that are capable of resolving many elements of a real transportation system. On the other hand, within the past few years, the theory of dynamic traffic assignments in terms of equilibrium existence and equilibrium computation has not matured to the point matching the model complexity inherent in simulations. In view of the above, this interdisciplinary seminar brought together leading scientists in the areas traffic simulations, algorithmic game theory and dynamic traffic assignment as well as people from industry with strong scientific background who identified possible ways to bridge the described gap

A differential game approach to urban drainage systems control

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Urban drainage systems (UDSs) are complex large-scale systems that carry stormwater and wastewater throughout urban areas. During heavy rain scenarios, UDSs are not able to handle the amount of extra water that enters the network and flooding occurs. Usually, this might happen because the network is not being used efficiently, i.e., some structures remain underused while many others are overused. This paper proposes a control methology based on differential game theory that aims to efficiently use the existing network elements in order to minimize overflows and properly manage the water resource. The proposed controller is tested on a typical UDS and is compared with a centralized MPC achieving similar results in terms of flooding minimization and network usage, but only using local information on distributed controllers.Peer ReviewedPostprint (author's final draft

Assessing action situation networks : a configurational perspective on water and energy governance in irrigation systems

Unidad de excelencia María de Maeztu MdM-2015-0552The action situation is a core component of actor-centered institutional analysis of natural resource governance. Institutional analysis frameworks have been extended to observe multiple situations structured into networks. If further operationalized, this extension can improve policy diagnosis of human-environmental interactions. This paper proposes two complementary ways to move in that direction. First, we propose the use of qualitative configurational analysis and game theory to study the interactions between situations and assess the contribution of each to a desired outcome. Second, we draw on centrality measures to assess the benefits and risks of implementing policies that aim to change the equilibria in action situations. Both analytical strategies are applied to two cases involving irrigation and energy governance. In the Spanish case, centrality of the water allocation situation justifies a configuration of drought measures that also tackle cooperation in monitoring and infrastructure maintenance. In the Indian case, groundwater governance and adequate infrastructure capacity provision are necessary preconditions to enable coordinated technology adoption, which facilitates incentives for regulated irrigation. In both the cases, some action situations' positive outcomes are necessary in every configuration to guarantee optimal equilibria in the network. In the context of energy-fed irrigation systems, the proposed analytical strategies permit integrating interactions between water use, energy use and food production decisions in policy diagnoses. The analysis can be extended to identify archetypes, network closure, as well as structural and functional connectivity of networks in social-ecological systems