A Formal Model of Arms Market with Cash-for-Favours

2014 ◽  
Vol 20 (3) ◽  
pp. 411-428 ◽  
Author(s):  
Partha Gangopadhyay
Keyword(s):  
Nash Equilibrium ◽  
Formal Model ◽  
Market Imperfections ◽  
Static Properties ◽  
Equilibrium Outcome ◽  
Arms Trade ◽  
Market Production ◽  
Choice Variable ◽  
First Time

AbstractBoth corruption and market imperfections are important facets of modern arms markets. In the standard literature of arms market, production, procurement, sales (exports) and purchases (imports) of arms take place in the shadow of corruption. Corruption is an integral part of the environment of the arms trade that exerts an influence upon the outcome in the arms market. In our work, we make corruption as a choice variable of the powerful players in the global arms market and examine the equilibrium consequence of corruption that is strategically chosen by armament firms. We develop a simple duopoly to characterize a perfect Nash equilibrium of cash-for-favors and establish perplexing comparative static properties of this equilibrium. The primary intuition here is that cash-for-favors can have serious impacts on the equilibrium of an oligopoly through their effects on the incentives of and constraints on individual firms. We offer a model of endogenous corruption, to our understanding for the first time, to examine the global arms market in order to establish that the equilibrium outcome in the arms market cannot be fully captured by the standard results of oligopoly. Researchers have to extremely careful in applying the standard tools of oligopoly to the arms market as our results suggest that endogenous corruption can reverse most of the known results of oligopoly.

scholarly journals Valuable Cheap Talk and Equilibrium Selection

Games ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 34 ◽  
Author(s):  
Julian Jamison
Keyword(s):  
Nash Equilibrium ◽  
Nash Equilibria ◽  
Formal Model ◽  
Equilibrium Selection ◽  
Cheap Talk ◽  
Fictitious Play ◽  
Meaningful Communication

Intuitively, we expect that players who are allowed to engage in costless communication before playing a game would be foolish to agree on an inefficient outcome amongst the set of equilibria. At the same time, however, such preplay communication has been suggested as a rationale for expecting Nash equilibria in general. This paper presents a plausible formal model of cheap talk that distinguishes and resolves these possibilities. Players are assumed to have an unlimited opportunity to send messages before playing an arbitrary game. Using an extension of fictitious play beliefs, minimal assumptions are made concerning which messages about future actions are credible and hence contribute to final beliefs. In this environment, it is shown that meaningful communication among players leads to a Nash equilibrium (NE) of the action game. Within the set of NE, efficiency then turns out to be a consequence of imposing optimality on the cheap talk portion of the extended game. This finding contrasts with previous “babbling” results.

Flexibility mechanisms and credit discounting

2003 ◽  
Vol 8 (2) ◽  
pp. 247-260 ◽  
Author(s):  
Sungwhee Shin ◽  
Sang-Chul Suh
Keyword(s):  
Climate Change ◽  
Game Theory ◽  
Nash Equilibrium ◽  
Kyoto Protocol ◽  
Cooperative Game ◽  
Cooperative Game Theory ◽  
International Treaties ◽  
Equilibrium Outcome

We consider the international treaties on climate change as self-enforcing agreements. Applying non-cooperative game theory, we interpret the UN framework Convention on Climate Change as a Nash equilibrium outcome of an international abatement game where only domestic abatement is allowed. The Kyoto Protocol is a Nash equilibrium outcome of the game where flexibility mechanisms are introduced. We also show that credit discounting on foreign abatement can Pareto improve the welfare of all countries.

scholarly journals TOWARDS THE ALGEBRAIC ANALYSIS OF HYPERLINK STRUCTURES

2003 ◽  
Vol 13 (06) ◽  
pp. 655-684
Author(s):  
ALEXANDER FRONK
Keyword(s):  
Formal Model ◽  
Easy Access ◽  
Static Properties ◽  
Document Structure ◽  
Algebraic Analysis ◽  
Algebraic Specifications ◽  
Media Objects

Structuring media objects such as text or graphics by means of XML is a broadly discussed issue in hypermedia modelling. Thereby, an entire hypermedia document is not only arranged in such a way that different developers may interchange data and have easy access to the inner structure of media objects. Moreover, utilizing a given document structure to find new possibilities of linking documents is a major concern. Formal approaches, however, rarely appear in this context. In this paper, we contribute to formally structuring media objects and their linkage, thereby aiming at analyzing hyperlink structures. That is, properties of hyperlink structures such as reachability, existence of certain paths through a hyperdocument, or dangling links may be verified mathematically in advance of implementing the hyperdocument. Algebraic specifications serve as a formal model which allows to obtain algebras reflecting hyperlink structures and which is open to analyze their static properties.

scholarly journals New perspectives on bias in polar questions

2017 ◽  
Vol 9 (1) ◽  
pp. 1-50 ◽  
Author(s):  
Beáta Gyuris
Keyword(s):  
Formal Model ◽  
Comprehensive Analysis ◽  
The Individual ◽  
First Time ◽  
Different Sources ◽  
Formal Features

Abstract The aim of this paper is to provide new insights for the analysis of bias in polar questions by showing that the distinction proposed by Sudo (2013) between evidential and epistemic biases leads to an integrated picture of the Hungarian system of polar interrogatives. For the first time, a comprehensive analysis of this system is given here and it is shown how the contributions of certain formal features, such as the interrogative and the negative particles, can be captured independently. This perspective helps to explain restrictions on the occurrences of the different forms of polar interrogatives in Hungarian with respect to a large number of question uses. The paper derives the biases associated with the individual constituents from different sources and makes some proposals on how their impact could be incorporated into a formal model of dialogue.

scholarly journals Supervisor-Worker Problems with an Application in Education

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1965
Author(s):  
Dorin Shmaryahu ◽  
Kobi Gal ◽  
Guy Shani
Keyword(s):  
Formal Model ◽  
Minimal Cost ◽  
Learning Session ◽  
E Learning ◽  
Multi Agent ◽  
Planning Task ◽  
Learning Software ◽  
First Time ◽  
Practice Skills ◽  
Multi Agent Planning

In many e-learning settings, allowing students to choose which skills to practice encourages their motivation and contributes to learning. However, when given choice, students may prefer to practice skills that they already master, rather than practice skills they need to master. On the other hand, requiring students only to practice their required skills may reduce their motivation and lead to dropout. In this paper, we model this tradeoff as a multi-agent planning task, which we call SWOPP (Supervisor- Worker Problem with Partially Overlapping goals), involving two agents—a supervisor (teacher) and a worker (student)—each with different, yet non-conflicting, goals. The supervisor and worker share joint goals (mastering skills). The worker plans to achieve his/her own goals (completing an e-learning session) at a minimal cost (effort required to solve problems). The supervisor guides the worker towards achieving the joint goals by controlling the problems in the choice set for the worker. We provide a formal model for the SWOPP task and two sound and complete algorithms for the supervisor to guide the worker’s plan to achieve their joint goals. We deploy SWOPP for the first time in a real-world study to personalize math questions for K5 students using an e-learning software in schools. We show that SWOPP was able to guide students’ interactions with the software to practice necessary skills without deterring their motivation.

scholarly journals Dynamics, morphogenesis and convergence of evolutionary quantum Prisoner's Dilemma games on networks

2016 ◽  
Vol 472 (2186) ◽  
pp. 20150280 ◽  
Author(s):  
Angsheng Li ◽  
Xi Yong
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Nash Equilibrium ◽  
Prisoner's Dilemma ◽  
Natural Extension ◽  
Prisoner’S Dilemma ◽  
Evolutionary Games ◽  
Many Body ◽  
The Many ◽  
First Time

The authors proposed a quantum Prisoner's Dilemma (PD) game as a natural extension of the classic PD game to resolve the dilemma. Here, we establish a new Nash equilibrium principle of the game, propose the notion of convergence and discover the convergence and phase-transition phenomena of the evolutionary games on networks. We investigate the many-body extension of the game or evolutionary games in networks. For homogeneous networks, we show that entanglement guarantees a quick convergence of super cooperation, that there is a phase transition from the convergence of defection to the convergence of super cooperation, and that the threshold for the phase transitions is principally determined by the Nash equilibrium principle of the game, with an accompanying perturbation by the variations of structures of networks. For heterogeneous networks, we show that the equilibrium frequencies of super-cooperators are divergent, that entanglement guarantees emergence of super-cooperation and that there is a phase transition of the emergence with the threshold determined by the Nash equilibrium principle, accompanied by a perturbation by the variations of structures of networks. Our results explore systematically, for the first time, the dynamics, morphogenesis and convergence of evolutionary games in interacting and competing systems.

scholarly journals A Multistage Process Model of How a Person Who Currently Injects Drugs Comes to Assist Persons Who Do not Inject with Their First Injections

2021 ◽  
Vol 6 ◽  
Author(s):  
Don C. Des Jarlais ◽  
Kamyar Arasteh ◽  
David M. Barnes ◽  
Jonathan Feelemyer ◽  
Hayley Berg ◽  
...  
Keyword(s):  
New York ◽  
Process Model ◽  
Formal Model ◽  
Statistical Testing ◽  
Odds Ratios ◽  
Moderate Amount ◽  
Staten Island ◽  
Multi Stage ◽  
Using Data ◽  
First Time

Injecting drugs for the first time almost always requires assistance from an experienced person who injects drugs (PWID). While there has been moderate amount of research on PWID who assist with first injections, most of this research has focused on identifying characteristics of PWID who assist with first injections. We do not have a formal model that describes how the minority of PWID come to assist do so, while the majority never assist. Through comparison of persons who did or did not recently assist with first injections using data from PWID in Tallinn, Estonia (N = 286) and Staten Island, New York City (N = 101), we developed a formal multi-stage model of how PWID come to assist with first injections. The model had a primary pathway 1) of engaging in “injection promoting” behaviors, 2) being asked to assist, and 3) assisting. Statistical testing using odds ratios showed participation in each stage was strongly associated with participation in the next stage (all odds ratios >3.0) and the probabilities of assisting significantly increased with participation in the successive stages. We then used the model to compare engagement in the stages pre-vs. post participation in an intervention, and to compare persons who recently assisted to persons who had assisted in the past but had not recently assisted and to persons who had never assisted. Advantages of a formal model for how current PWID come to assist with first injections include: facilitating comparisons across different PWID populations and assessing strengths and limitations of interventions to reduce assisting with first injections.

scholarly journals Cooperación en los dilemas sociales / Cooperation in Social Dilemmas

2012 ◽  
Vol 1 (2) ◽  
Author(s):  
Juan Carlos Aguado Franco ◽  
David De las Heras Camino
Keyword(s):  
Nash Equilibrium ◽  
Prisoner's Dilemma ◽  
Social Dilemmas ◽  
Prisoner’S Dilemma ◽  
Equilibrium Outcome ◽  
Second Person ◽  
Mutual Cooperation ◽  
Relative Value ◽  
Chicken Game ◽  
Assurance Game

ABSTRACTSocial dilemmas are situations in which individual rationality leads to collective irrationality. Prisoner's Dilemma is the best-known game depicting situations of this sort, but there are other such games. Two other games can be created by switching the relative value of the outcomes: the Assurance Game and the Chicken Game. Whereas mutual cooperation is the goal for the Prisoner's Dilemma Game and the Assurance Game, that is not necessarily the case for the Chicken Game; if one person can provide a joint benefit, then it may make no sense for the second person to duplicate the effort. In the iterated Prisoner's Dilemma, cooperation may arise as an equilibrium outcome. If the game result is infinitely repeated, cooperation may be a Nash equilibrium although both players defecting always remains an equilibrium. Multiple-person social dilemmas are examined.RESUMENLos dilemas sociales, esas situaciones en las que la racionalidad individual lleva a una irracionalidad colectiva, se han planteado generalmente en la literatura económica, de una manera comprensible e intuitiva, a través del “dilema del prisionero”, si bien existen otros juegos que presentan también la forma de dilemas sociales. En efecto, partiendo de un dilema del prisionero, y modificando ligeramente los valores relativos de los pagos, podemos encontrar dos tipos de juegos diferentes: el de coordinación o seguro y el juego del “gallina”. Los distintos modelos dependerán de los supuestos que se realicen acerca de la situación analizada, lo que conducirá a extraer, lógicamente, conclusiones muy diferentes. Además, aunque la mutua cooperación es la meta clara tanto para el “dilema del prisionero” como para el juego de coordinación, esto no necesariamente se cumple para el “juego del gallina”; si una persona puede producir ese beneficio común, no tiene sentido que el otro duplique los esfuerzos. En efecto, en este tipo de juegos, los equilibrios de Nash en estrategias puras se producen en aquellas situaciones en las que uno coopera y el otro no lo hace. Aunque el análisis de los dilemas sociales, a través del dilema del prisionero bipersonal ayuda a arrojar luz sobre el asunto, parece oportuno profundizar la investigación en dos aspectos: la consideración de un horizonte temporal superior a una única partida, y la incorporación de un número de participantes en el juego mayor que dos, lo que presenta interesantes dificultades conceptuales.

scholarly journals Transaction Fees, Block Size Limit, and Auctions in Bitcoin

Ledger ◽  
2019 ◽  
Vol 4 ◽  
Author(s):  
Nicola Dimitri
Keyword(s):  
Nash Equilibrium ◽  
Block Size ◽  
Complete Information ◽  
Revenue Maximization ◽  
Equilibrium Outcome ◽  
Trade Off ◽  
Size Limit ◽  
Block Space ◽  
Transaction Fees ◽  
Auction Game

Confirmation of Bitcoin transactions is executed in blocks, which are then stored in the Blockchain. As compared to the number of transactions in the mempool, the set of transactions which are verified but not yet confirmed, available space for inclusion in a block is typically limited. For this reason, successful miners can only process a subset of such transactions, and users compete with each other to enter the next block by offering confirmation fees. Assuming that successful miners pursue revenue maximization, they will include in the block those mempool transactions that maximize earnings from related fees. In the paper we model transaction fees as a Nash Equilibrium outcome of an auction game with complete information. In the game the successful miner acts as an auctioneer selling block space, and users bid for shares of such space to confirm their transactions. Moreover, based on expected fees we also discuss what the optimal, revenue maximizing, block size limit should be for the successful miner. Consistently with the intuition, the optimal block size limit resolves the trade-off between including additional transactions (which possibly lower the unit fees collected) and keeping the block capacity limited (with, however, higher unit fees).

scholarly journals Insert Switches Inside to Increase Battery Lifespan

2020 ◽  
Vol 5 (2) ◽  
pp. 201-209
Author(s):  
Christophe Savard ◽  
Pascal Venet ◽  
Eric Niel ◽  
Laurent Pietrac ◽  
Ali Sari
Keyword(s):  
Formal Model ◽  
Cell Model ◽  
Electrical Energy ◽  
Cell Aging ◽  
Fundamental Parameters ◽  
Electric Model ◽  
Behavioral Parameters ◽  
A Cell ◽  
The Impact ◽  
First Time

This paper shows the possible gain on time before the end of useful time brought by switches addition in a multicell battery. In a first time, it presents a battery electric model. A battery includes many identical electrical energy cells that electrically interact. From a behavioral standpoint, cell performance is measured by fundamental parameters: State of Charge (SoC) and State of Health (SoH). To simulate cell electrical behavior, the Thevenin model or the Nernst model are often used. However, these models do not take into account the cells aging or the possible interactions on aging. A cell ages mainly in two ways: cyclic and calendar. This aging impacts both the elements of the equivalent electrical model and the fundamental parameters (SoC and SoH). Thus, the conventional electric model of a cell does not accurately reflect the cell aging. In this paper, another formal model based on the fundamental curve that relates electrical and behavioral parameters is proposed. It integrates aging into the equivalent electric model estimation. In a second time, in order to validate this model, this cell model is used to simulate parallel-series association. To improve battery lifespan, in addition to the usual balancing techniques, it may be relevant to require some traditional reliability and operating safety solutions. This requires to add switches inside battery. The presented simulation shows adding switches solution is currently not deployed. This is justified in this paper by examining the impact provide on lifespan improvement on an example, which is pretty weak. But it also shows that however, by managing active cells in a different way, adding switches and spare cells can really reach this improvement.

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