Essays on social networks and cooperation: the case of natural resources
- Autores: Jorge Marco Renau
- Directores de la Tesis: Renan-Ulrich Goetz (dir. tes.)
- Lectura: En la Universitat de Girona ( España ) en 2018
- Idioma: español
- Tribunal Calificador de la Tesis: Santiago J. Rubio Jorge (presid.), Dolors Berga (secret.), Montserrat Viladrich Grau (voc.)
- Programa de doctorado: Programa de Doctorado en Derecho, Economía y Empresa por la Universidad de Girona y la Universidad de Vic-Universidad Central de Catalunya
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
The tragedy of the commons is a concept used in environmental economics to highlight the conflict between individual and collective rationality. The tragedy occurs when a natural resource is easily available to all users and every user tries to reap the greatest short-term benefit from the resource. In situations of this kind, demand greatly outweighs replenishment and eventually the natural resource will be unavailable for the users. From the 1990s onwards, scholars have found many examples that suggest that agents are capable of overcoming the tragedy of the commons and sustaining the natural resource. Examples include resource property rights and community management through collective action. This thesis focuses on collective action and the determinants of cooperation. At the community level, many factors impacting cooperation (i.e., trust, communication, social pressure) are very dependent on the underlying structure of social interactions, often formalized by a social network. The aim of this thesis is to assess social networks and their explicit role in the emergence and maintenance of cooperation in resource use. This is done by coupling resource stock dynamics with social dynamics concerning compliance to a cooperative norm prescribing the socially optimal use of the natural resource. Among the single aspects analyzed in the literature, cohesiveness and the share of norm-complying agents (compliers) stand out. The definition for cohesiveness is most frequently based on links between agents. However, in the case of cooperativeness or the exercise of social pressure, not only are the links between agents important, but so too are the agents’ chosen strategies. If two compliers are linked, one can expect they will experience greater social pressure than if every complier were linked to a defector but not linked between them. For this reason, we propose a new connectivity measure that is based on links and the strategy chosen. We have called it “local cohessiveness of compliers” as it considers the links between the compliers in the neighborhood of an agent. As such it is a “small-world or micro” characteristic of the social network and is different from more “large-world or macro” characteristics such as the degree, size or density.
Although the share of compliers is often seen as the most important driving force for cooperativeness, it is independent of the network size and density. As such, its indicative power to foresee a possible propagation of compliers within social networks is likely to be limited. The asymmetry and irregularity of real social networks suggests that merely focusing on a single aspect of the network does not offer a reliable instrument to accurately analyze the range of cooperativeness. For these reasons, we analyze the underlying forces of cooperation by evaluating to what extent macro and micro characteristics of the structure of social interaction support social norms. In our models, macro and micro characteristics of social interaction lead to social pressure that depends on the share of compliers, the local cohesiveness of compliers and the state of the natural resource. The consideration of monetary or non-monetary punishment leads to a second important question. In particular, it allows analyzing the question to what extent pro-social behavior can be induced by informal enforcement (social pressure) or by legal enforcement (taxes or subsidies). Our analysis shed new light on this question by determining the conditions where only legal enforcement is able to induce cooperativeness and the conditions where informal and legal enforcement are both able to support cooperativeness. Likewise, it offers a concept to measure their substitutability. How to best design network-orientated policies to promote cooperation within the community remains an interesting topic for future research. Apart from addressing policies-related questions this research contributes to the understanding of drivers of cooperation in relation with social networks in several ways: (i) we link dynamic economic decision problems with different classes of social networks to study their effect on the decision problem, (ii) our study offers a metric for the cohesiveness of compliers – as opposed to social ties – and determines its influence on cooperativeness between the agents, and (iii) our models offer an equilibrium concept and determine the possible equilibria as a function of different classes of social networks, the evolution of a stock variable and dynamic strategy choices by the agents.
