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- Creators: Motsch, Sebastien
Description
Need-based transfers (NBTs) are a form of risk-pooling in which binary welfare exchanges
occur to preserve the viable participation of individuals in an economy, e.g. reciprocal gifting
of cattle among East African herders or food sharing among vampire bats. With the
broad goal of better understanding the mathematics of such binary welfare and risk pooling,
agent-based simulations are conducted to explore socially optimal transfer policies
and sharing network structures, kinetic exchange models that utilize tools from the kinetic
theory of gas dynamics are utilized to characterize the wealth distribution of an NBT economy,
and a variant of repeated prisoner’s dilemma is analyzed to determine whether and
why individuals would participate in such a system of reciprocal altruism.
From agent-based simulation and kinetic exchange models, it is found that regressive
NBT wealth redistribution acts as a cutting stock optimization heuristic that most efficiently
matches deficits to surpluses to improve short-term survival; however, progressive
redistribution leads to a wealth distribution that is more stable in volatile environments and
therefore is optimal for long-term survival. Homogeneous sharing networks with low variance
in degree are found to be ideal for maintaining community viability as the burden and
benefit of NBTs is equally shared. Also, phrasing NBTs as a survivor’s dilemma reveals
parameter regions where the repeated game becomes equivalent to a stag hunt or harmony
game, and thus where cooperation is evolutionarily stable.
occur to preserve the viable participation of individuals in an economy, e.g. reciprocal gifting
of cattle among East African herders or food sharing among vampire bats. With the
broad goal of better understanding the mathematics of such binary welfare and risk pooling,
agent-based simulations are conducted to explore socially optimal transfer policies
and sharing network structures, kinetic exchange models that utilize tools from the kinetic
theory of gas dynamics are utilized to characterize the wealth distribution of an NBT economy,
and a variant of repeated prisoner’s dilemma is analyzed to determine whether and
why individuals would participate in such a system of reciprocal altruism.
From agent-based simulation and kinetic exchange models, it is found that regressive
NBT wealth redistribution acts as a cutting stock optimization heuristic that most efficiently
matches deficits to surpluses to improve short-term survival; however, progressive
redistribution leads to a wealth distribution that is more stable in volatile environments and
therefore is optimal for long-term survival. Homogeneous sharing networks with low variance
in degree are found to be ideal for maintaining community viability as the burden and
benefit of NBTs is equally shared. Also, phrasing NBTs as a survivor’s dilemma reveals
parameter regions where the repeated game becomes equivalent to a stag hunt or harmony
game, and thus where cooperation is evolutionarily stable.
ContributorsKayser, Kirk (Author) / Armbruster, Dieter (Thesis advisor) / Lampert, Adam (Committee member) / Ringhofer, Christian (Committee member) / Motsch, Sebastien (Committee member) / Gardner, Carl (Committee member) / Arizona State University (Publisher)
Created2018
Description
One of the salient challenges of sustainability is the Tragedy of the Commons, where individuals acting independently and rationally deplete a common resource despite their understanding that it is not in the group's long term best interest to do so. Hardin presents this dilemma as nearly intractable and solvable only by drastic, government-mandated social reforms, while Ostrom's empirical work demonstrates that community-scale collaboration can circumvent tragedy without any elaborate outside intervention. Though more optimistic, Ostrom's work provides scant insight into larger-scale dilemmas such as climate change. Consequently, it remains unclear if the sustainable management of global resources is possible without significant government mediation. To investigate, we conducted two game theoretic experiments that challenged students in different countries to collaborate digitally and manage a hypothetical common resource. One experiment involved students attending Arizona State University and the Rochester Institute of Technology in the US and Mountains of the Moon University in Uganda, while the other included students at Arizona State and the Management Development Institute in India. In both experiments, students were randomly assigned to one of three production roles: Luxury, Intermediate, and Subsistence. Students then made individual decisions about how many units of goods they wished to produce up to a set maximum per production class. Luxury players gain the most profit (i.e. grade points) per unit produced, but they also emit the most externalities, or social costs, which directly subtract from the profit of everybody else in the game; Intermediate players produce a medium amount of profit and externalities per unit, and Subsistence players produce a low amount of profit and externalities per unit. Variables influencing and/or inhibiting collaboration were studied using pre- and post-game surveys. This research sought to answer three questions: 1) Are international groups capable of self-organizing in a way that promotes sustainable resource management?, 2) What are the key factors that inhibit or foster collective action among international groups?, and 3) How well do Hardin's theories and Ostrom's empirical models predict the observed behavior of students in the game? The results of gameplay suggest that international cooperation is possible, though likely sub-optimal. Statistical analysis of survey data revealed that heterogeneity and levels of trust significantly influenced game behavior. Specific traits of heterogeneity among students found to be significant were income, education, assigned production role, number of people in one's household, college class, college major, and military service. Additionally, it was found that Ostrom's collective action framework was a better predictor of game outcome than Hardin's theories. Overall, this research lends credence to the plausibility of international cooperation in tragedy of the commons scenarios such as climate change, though much work remains to be done.
ContributorsStanton, Albert Grayson (Author) / Clark, Susan Spierre (Thesis director) / Seager, Thomas (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2014-12
Description
This dissertation investigates the dynamics of evolutionary games based on the framework of interacting particle systems in which individuals are discrete, space is explicit, and dynamics are stochastic. Its focus is on 2-strategy games played on a d-dimensional integer lattice with a range of interaction M. An overview of related past work is given along with a summary of the dynamics in the mean-field model, which is described by the replicator equation. Then the dynamics of the interacting particle system is considered, first when individuals are updated according to the best-response update process and then the death-birth update process. Several interesting results are derived, and the differences between the interacting particle system model and the replicator dynamics are emphasized. The terms selfish and altruistic are defined according to a certain ordering of payoff parameters. In these terms, the replicator dynamics are simple: coexistence occurs if both strategies are altruistic; the selfish strategy wins if one strategy is selfish and the other is altruistic; and there is bistability if both strategies are selfish. Under the best-response update process, it is shown that there is no bistability region. Instead, in the presence of at least one selfish strategy, the most selfish strategy wins, while there is still coexistence if both strategies are altruistic. Under the death-birth update process, it is shown that regardless of the range of interactions and the dimension, regions of coexistence and bistability are both reduced. Additionally, coexistence occurs in some parameter region for large enough interaction ranges. Finally, in contrast with the replicator equation and the best-response update process, cooperators can win in the prisoner's dilemma for the death-birth process in one-dimensional nearest-neighbor interactions.
ContributorsEvilsizor, Stephen (Author) / Lanchier, Nicolas (Thesis advisor) / Kang, Yun (Committee member) / Motsch, Sebastien (Committee member) / Smith, Hal (Committee member) / Thieme, Horst (Committee member) / Arizona State University (Publisher)
Created2016
Description
We develop a unique model for household preferences in a three good market of television content (cable), internet content (Netflix), and income spent on any other good or activity. Utility is a function of the time spent viewing television content, time spent viewing internet content, and income spent otherwise. Preferences are determined by the complementarity (or substitutability) of television and internet content, the complementarity of viewing content and spending income otherwise, and individual preference for income. Consumers maximize utility subject to time of viewership and budget constraints. We analyze the comparative statics of the model by varying the complementarity between television and internet content and the complementarity between viewing content and spending income otherwise. We develop a model of firms, in which there are two firms offering one product each who compete on price. They charge a flat-fee for their product (either television or internet content) and have a fixed cost. Their revenue is determined by the number of consumers who choose to purchase their product multiplied by the price they charge. We find a collusive outcome for the firms. We analyze the Nash Equilibrium of the model. We only found symmetric Mixed Action Nash Equilibria (MANE), with the following interesting feature: Bertrand Competition causes firms to choose low prices very often, but firms price significantly higher should the price drop too low. Thus, the MANE places high probability mass on the lowest and highest prices of each firm but has little mass elsewhere.
ContributorsWeser, Daniel James (Author) / Leiva Bertran, Fernando (Thesis director) / Mendez, Jose (Committee member) / Department of Economics (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05