如果你也在 怎样代写博弈论Game Theory这个学科遇到相关的难题,请随时右上角联系我们的24/7代写客服。
博弈论是对理性主体之间战略互动的数学模型的研究。它在社会科学的所有领域,以及逻辑学、系统科学和计算机科学中都有应用。最初,它针对的是两人的零和博弈,其中每个参与者的收益或损失都与其他参与者的收益或损失完全平衡。在21世纪,博弈论适用于广泛的行为关系;它现在是人类、动物以及计算机的逻辑决策科学的一个总称。
statistics-lab™ 为您的留学生涯保驾护航 在代写博弈论Game Theory方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写博弈论Game Theory代写方面经验极为丰富,各种代写博弈论Game Theory相关的作业也就用不着说。
我们提供的博弈论Game Theory及其相关学科的代写,服务范围广, 其中包括但不限于:
- Statistical Inference 统计推断
- Statistical Computing 统计计算
- Advanced Probability Theory 高等概率论
- Advanced Mathematical Statistics 高等数理统计学
- (Generalized) Linear Models 广义线性模型
- Statistical Machine Learning 统计机器学习
- Longitudinal Data Analysis 纵向数据分析
- Foundations of Data Science 数据科学基础
经济代写|博弈论代写Game Theory代考|Solution Concepts
Since EFGs can be converted into NFGs, the solution concepts introduced in Section 2.3.1 still apply. Also, there are other solution concepts specifically for EFGs. We briefly introduce some of them at a high level.
One solution concept is subgame perfect equilibrium (or subgame perfect Nash equilibrium, SPE in short). It is a refinement of NE. This means the set of SPE is a subset of NE. A strategy profile is an SPE equilibrium if, in every subgame of the original game, the strategies remain an NE. A subgame is defined as the partial tree consisting of a node and all its successors, with the requirement that the root node of the partial tree is the only node in its information set. This means if the players play a small game that is part of the original game, they still have no incentive to deviate from their current strategy. A subgame can be a subgame of another subgame rooted at its ancestor node. A finite EFG with perfect recall always has an SPE. To find an SPE in a finite game with perfect information, one can use backward induction as all the information sets are singletons. First, consider the smallest subgames rooted at a parent node of a terminal node. After solving these subgames by determining the action to maximize the acting player’s expected utility, one can solve a slightly larger subgame whose subgames have already been solved, assuming the player will play according to the smaller subgames’ solution. This process continues until the original game is solved. The resulting strategy is an SPE. For games of imperfect or incomplete information, backward induction cannot be applied as it will require reasoning about the information sets with more than one node. The SPE concept can also be defined through the one-shot deviation principle: a strategy profile is an SPE if and only if no player can gain any utility by deviating from their strategy for just one decision point and then reverting back to their strategy in any subgame.
In the example game in Figure $2.1$, if we remove the dashed box, the game becomes one with perfect information, and it has two subgames in addition to the original game, with the root nodes being nodes 2 and 3 respectively. In this new game, Player 1 choosing $L$ and Player 2 choosing $r$ at both nodes 2 and 3 is an NE but not an SPE, because, in the subgame rooted at node 3 , Player 2 choosing $r$ is not the best action. In contrast, Player 1 choosing $R$ and Player 2 choosing $r$ at node 2 , 1 at node 3 is an SPE.
Another solution concept is sequential equilibrium (Kreps and Wilson 1982), which is a further refinement of SPE. A sequential equilibrium consists of not only the players’ strategies but also the players’ beliefs for each information set. The belief describes a probability distribution on the nodes in the information set since the acting player cannot distinguish them when they play the game. Unlike SPE which only considers the subgames rooted from a node that is the only element in its information set, the sequential equilibrium requires that the players are sequentially rational and takes the best action in terms of expected utility concerning the belief at every information set even if it is not a singleton.
经济代写|博弈论代写Game Theory代考|Stackelberg Game
Consider a two-player NFG with finite actions. The two players choose an action in their action set simultaneously without knowing the other player’s strategy ahead of time. In an NE of the game, each player’s strategy is a best response to the other player’s strategy. But what if one player’s strategy is always known to other players ahead of time? This kind of role asymmetry is depicted in a Stackelberg game.
In a Stackelberg game, one player is the leader and chooses her strategy first, and the other players are followers who observe the leader’s strategy and then choose their strategies. The leader has to commit to the strategy she chooses, i.e. she cannot announce a strategy to the followers and play a different strategy when the game is actually played. She can commit to either a pure strategy or a mixed strategy. If she commits to a mixed strategy, the followers can observe her mixed strategy but not the realization of sampled action from this mixed strategy. A Stackelberg game can be described in the same way as before, with a tuple $(\mathcal{N}, \mathcal{A}, u)$ for games in normal form and $(\mathcal{N}, \mathcal{A}, \mathcal{H}, \mathcal{Z}, \chi, \rho, \sigma, u)$ for games in extensive form, with the only difference that one of the players (usually Player 1 ) is assumed to be the leader.
At first sight, one may think that the followers have an advantage as they have more information than the leader when they choose their strategies. However, it is not the case. Consider the Football vs. Concert game again. If the row player is the leader and commits to choosing the action $\mathrm{F}$, a rational column player will choose action $\mathrm{F}$ to ensure a positive payoff. Thus, the row player guarantees herself a utility of 2, the highest utility she can get in this game, through committing to playing pure strategy F. In the real world, it is common to see similar scenarios. When a couple is deciding what to do during the weekend, if one of them has a stronger opinion and insists on going to the activity he or she prefers, they will likely choose that activity in the end. In this example game, the leader ensures a utility that equals the best possible utility she can get in an NE. In some other games, the leader can get a utility higher than any NE in the game by committing to a good strategy. In the example game in Table $2.5$ (Up, Right) is the only NE, with the row player’s utility being 4 . However, if the row player is the leader and commits to a uniform random strategy, the column player will choose Left as a best response, yielding an expected utility of 5 for the row player. This higher expected utility for the row players shows the power of commitment.
经济代写|博弈论代写Game Theory代考|Solution Concept
As shown in the example, NEs are no longer well suited to prescribe the behavior of players in a Stackelberg game. Instead, the concept of Stackelberg equilibrium is used. A Stackelberg equilibrium in a two-player Stackelberg game is a strategy profile where the follower best responds to the leader’s strategy, and the leader commits to a strategy that can maximize her expected utility, knowing that the follower will best respond. One subtle part of this definition is the tie-breaking rule. There can be multiple best responses. Although they lead to the same expected utility for the follower, they can result in different expected utility for the leader. Therefore, to define a Stackelberg equilibrium, we need to specify a best response function that maps a leader’s strategy to the follower’s best response strategy.
Definition $2.5$ (Best Response Function): $f: S_{1} \mapsto S_{2}$ is a best response function if and only if $u_{2}\left(s_{1}, f\left(s_{1}\right)\right) \geq u_{2}\left(s_{1}, s_{2}\right), \forall s_{1} \in S_{1}, s_{2} \in S_{2}$
Since the expected utility of playing a mixed strategy is a linear combination of the expected utility of playing the pure strategies in its support, the constraint is equivalent to $u_{2}\left(s_{1}, f\left(s_{1}\right)\right) \geq u_{2}\left(s_{1}, a_{2}\right), \forall s_{1} \in S_{1}, a_{2} \in A_{2}$. The Stackelberg equilibrium is defined based on the best response function definition.
Definition 2.6 (Stackelberg Equilibrium): A strategy profile $s=\left(s_{1}, f\left(s_{1}\right)\right)$ is a Stackelberg equilibrium if $f$ is a best response function and $u_{1}\left(s_{1}, f\left(s_{1}\right)\right) \geq u_{1}\left(s_{1}^{\prime}, f\left(s_{1}^{\prime}\right)\right), \forall s_{1}^{\prime} \in S_{1}$.
For some best response functions, the corresponding Stackelberg equilibrium may not exist. A commonly used best response function is one that breaks ties in favor of the leader. The resulting equilibrium is called the strong Stackelberg equilibrium (SSE).
Definition $2.7$ (Strong Stackelberg Equilibrium (SSE)): A strategy profile $s=\left(s_{1}, f\left(s_{1}\right)\right.$ ) is a strong Stackelberg equilibrium if
- $u_{2}\left(s_{1}, f\left(s_{1}\right)\right) \geq u_{2}\left(s_{1}, s_{2}\right), \forall s_{1} \in S_{1}, s_{2} \in S_{2}$ (attacker best responds)
- $u_{1}\left(s_{1}, f\left(s_{1}\right)\right) \geq u_{1}\left(s_{1}, s_{2}\right), \forall s_{1} \in S_{1}, s_{2} \in B R\left(s_{1}\right)$ (tie-breaking is in favor of the leader)
- $u_{1}\left(s_{1}, f\left(s_{1}\right)\right) \geq u_{1}\left(s_{1}^{\prime}, f\left(s_{1}^{\prime}\right)\right), \forall s_{1}^{\prime} \in S_{1}$ (leader maximizes her expected utility)
SSE is guaranteed to exist in two-player finite games. The weak Stackelberg equilibrium (WSE) can be defined in a similar way, with a tie-breaking rule against the leader. However, WSE may not exist in some games. SSE in two-player normal-form Stackelberg games can be computed in polynomial time through solving multiple linear programs, each corresponding to a possible best response of the follower (Conitzer and Sandholm 2006).
博弈论代考
经济代写|博弈论代写Game Theory代考|Solution Concepts
由于 EFG 可以转换为 NFG,因此第 2.3.1 节中介绍的解决方案概念仍然适用。此外,还有其他专门针对 EFG 的解决方案概念。我们简要介绍其中的一些。
一种解决方案的概念是子博弈完美均衡(或子博弈完美纳什均衡,简称 SPE)。这是NE的改进。这意味着 SPE 的集合是 NE 的子集。如果在原始博弈的每个子博弈中,策略仍然是 NE,则策略配置文件是 SPE 均衡。子博弈定义为由一个节点及其所有后继节点组成的部分树,要求部分树的根节点是其信息集中的唯一节点。这意味着如果玩家玩的小游戏是原始游戏的一部分,他们仍然没有动力偏离他们当前的策略。子博弈可以是根植于其祖先节点的另一个子博弈的子博弈。具有完美召回率的有限 EFG 始终具有 SPE。要在具有完美信息的有限博弈中找到 SPE,可以使用反向归纳,因为所有信息集都是单例的。首先,考虑以终端节点的父节点为根的最小子博弈。在通过确定最大化行动玩家的期望效用的动作来解决这些子博弈之后,假设玩家将根据较小的子博弈的解决方案进行游戏,则可以解决其子博弈已经解决的稍大的子博弈。这个过程一直持续到原始游戏被解决。由此产生的策略是 SPE。对于不完整或不完整信息的博弈,不能应用反向归纳,因为它需要对具有多个节点的信息集进行推理。SPE 的概念也可以通过一次性偏差原则来定义:
在图中的示例游戏中2.1,如果我们去掉虚线框,博弈就变成了一个信息完全的博弈,除了原来的博弈,它还有两个子博弈,根节点分别是节点2和3。在这个新游戏中,玩家 1 选择大号和玩家 2 选择r在节点 2 和 3 处都是 NE 但不是 SPE,因为在以节点 3 为根的子博弈中,玩家 2 选择r不是最好的动作。相比之下,玩家 1 选择R和玩家 2 选择r在节点 2 处,节点 3 处的 1 是 SPE。
另一个解决方案概念是顺序平衡(Kreps 和 Wilson 1982),它是 SPE 的进一步改进。顺序均衡不仅包括参与者的策略,还包括参与者对每个信息集的信念。信念描述了信息集中节点上的概率分布,因为行动玩家在玩游戏时无法区分它们。与 SPE 仅考虑源自其信息集中唯一元素的节点的子博弈不同,顺序均衡要求参与者是顺序理性的,并且在与每个信息集中的信念有关的预期效用方面采取最佳行动,即使它不是单例。
经济代写|博弈论代写Game Theory代考|Stackelberg Game
考虑一个具有有限动作的两人 NFG。两个玩家同时在他们的行动集中选择一个行动,而无需提前知道另一个玩家的策略。在游戏的 NE 中,每个玩家的策略都是对其他玩家策略的最佳响应。但是,如果一个玩家的策略总是被其他玩家提前知道怎么办?在 Stackelberg 游戏中描述了这种角色不对称。
在 Stackelberg 博弈中,一个玩家是领导者,首先选择她的策略,其他玩家是跟随者,他们观察领导者的策略,然后选择他们的策略。领导者必须承诺她选择的策略,即她不能向追随者宣布策略并在实际玩游戏时采取不同的策略。她可以采用纯策略或混合策略。如果她采用混合策略,则追随者可以观察到她的混合策略,但不能从这种混合策略中观察到抽样行动的实现。Stackelberg 游戏可以像以前一样用元组来描述(ñ,一个,在)对于正常形式的游戏和(ñ,一个,H,从,χ,ρ,σ,在)对于广泛形式的游戏,唯一的区别是其中一名玩家(通常是玩家 1 )被假定为领导者。
乍一看,人们可能会认为追随者具有优势,因为他们在选择策略时比领导者拥有更多的信息。然而,事实并非如此。再次考虑足球与音乐会比赛。如果排球员是领导者并承诺选择行动F,一个理性的专栏玩家会选择行动F以确保获得积极的回报。因此,排位玩家通过致力于玩纯策略 F 来保证自己的效用为 2,这是她在这场游戏中可以获得的最高效用。在现实世界中,经常会看到类似的场景。当一对夫妇在决定周末做什么时,如果其中一个人有更强烈的意见并坚持参加他或她喜欢的活动,他们最终可能会选择那个活动。在这个示例游戏中,领导者确保效用等于她在 NE 中可以获得的最佳效用。在其他一些游戏中,领导者可以通过制定好的策略获得比游戏中任何 NE 更高的效用。在表中的示例游戏中2.5(Up, Right) 是唯一的 NE,行玩家的效用是 4 。但是,如果行玩家是领导者并承诺采用统一随机策略,则列玩家将选择左作为最佳响应,从而为行玩家产生 5 的预期效用。这种对排球员的更高预期效用显示了承诺的力量。
经济代写|博弈论代写Game Theory代考|Solution Concept
如示例所示,NE 不再适合在 Stackelberg 博弈中规定玩家的行为。相反,使用了斯塔克伯格均衡的概念。两人 Stackelberg 博弈中的 Stackelberg 均衡是一种策略配置文件,其中追随者对领导者的策略做出最好的反应,而领导者在知道追随者会做出最佳反应的情况下,承诺可以最大化她的预期效用的策略。这个定义的一个微妙部分是平局规则。可以有多个最佳响应。尽管它们为追随者带来相同的预期效用,但它们可能导致领导者的预期效用不同。因此,要定义 Stackelberg 均衡,我们需要指定一个最佳响应函数,将领导者的策略映射到追随者的最佳响应策略。
定义2.5(最佳响应函数):F:小号1↦小号2是一个最佳响应函数当且仅当在2(s1,F(s1))≥在2(s1,s2),∀s1∈小号1,s2∈小号2
由于采用混合策略的预期效用是在其支持下采用纯策略的预期效用的线性组合,因此约束等价于在2(s1,F(s1))≥在2(s1,一个2),∀s1∈小号1,一个2∈一个2. Stackelberg 平衡是根据最佳响应函数定义来定义的。
定义 2.6(斯塔克伯格均衡):战略概况s=(s1,F(s1))是一个 Stackelberg 均衡如果F是一个最佳响应函数并且在1(s1,F(s1))≥在1(s1′,F(s1′)),∀s1′∈小号1.
对于某些最佳响应函数,可能不存在相应的 Stackelberg 平衡。一种常用的最佳响应函数是打破关系以支持领导者的函数。由此产生的平衡称为强斯塔克伯格平衡(SSE)。
定义2.7(Strong Stackelberg Equilibrium (SSE)):战略概况s=(s1,F(s1)) 是一个强 Stackelberg 均衡,如果
- 在2(s1,F(s1))≥在2(s1,s2),∀s1∈小号1,s2∈小号2(攻击者最佳响应)
- 在1(s1,F(s1))≥在1(s1,s2),∀s1∈小号1,s2∈乙R(s1)(打破平局有利于领导者)
- 在1(s1,F(s1))≥在1(s1′,F(s1′)),∀s1′∈小号1(领导者最大化她的期望效用)
SSE 保证存在于两人有限博弈中。弱斯塔克伯格均衡(WSE)可以用类似的方式定义,对领导者有一个打破平局的规则。但是,某些游戏中可能不存在 WSE。两人范式 Stackelberg 游戏中的 SSE 可以通过求解多个线性程序在多项式时间内计算,每个线性程序对应于跟随者的可能最佳响应(Conitzer 和 Sandholm 2006)。
统计代写请认准statistics-lab™. statistics-lab™为您的留学生涯保驾护航。
金融工程代写
金融工程是使用数学技术来解决金融问题。金融工程使用计算机科学、统计学、经济学和应用数学领域的工具和知识来解决当前的金融问题,以及设计新的和创新的金融产品。
非参数统计代写
非参数统计指的是一种统计方法,其中不假设数据来自于由少数参数决定的规定模型;这种模型的例子包括正态分布模型和线性回归模型。
广义线性模型代考
广义线性模型(GLM)归属统计学领域,是一种应用灵活的线性回归模型。该模型允许因变量的偏差分布有除了正态分布之外的其它分布。
术语 广义线性模型(GLM)通常是指给定连续和/或分类预测因素的连续响应变量的常规线性回归模型。它包括多元线性回归,以及方差分析和方差分析(仅含固定效应)。
有限元方法代写
有限元方法(FEM)是一种流行的方法,用于数值解决工程和数学建模中出现的微分方程。典型的问题领域包括结构分析、传热、流体流动、质量运输和电磁势等传统领域。
有限元是一种通用的数值方法,用于解决两个或三个空间变量的偏微分方程(即一些边界值问题)。为了解决一个问题,有限元将一个大系统细分为更小、更简单的部分,称为有限元。这是通过在空间维度上的特定空间离散化来实现的,它是通过构建对象的网格来实现的:用于求解的数值域,它有有限数量的点。边界值问题的有限元方法表述最终导致一个代数方程组。该方法在域上对未知函数进行逼近。[1] 然后将模拟这些有限元的简单方程组合成一个更大的方程系统,以模拟整个问题。然后,有限元通过变化微积分使相关的误差函数最小化来逼近一个解决方案。
tatistics-lab作为专业的留学生服务机构,多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务,包括但不限于Essay代写,Assignment代写,Dissertation代写,Report代写,小组作业代写,Proposal代写,Paper代写,Presentation代写,计算机作业代写,论文修改和润色,网课代做,exam代考等等。写作范围涵盖高中,本科,研究生等海外留学全阶段,辐射金融,经济学,会计学,审计学,管理学等全球99%专业科目。写作团队既有专业英语母语作者,也有海外名校硕博留学生,每位写作老师都拥有过硬的语言能力,专业的学科背景和学术写作经验。我们承诺100%原创,100%专业,100%准时,100%满意。
随机分析代写
随机微积分是数学的一个分支,对随机过程进行操作。它允许为随机过程的积分定义一个关于随机过程的一致的积分理论。这个领域是由日本数学家伊藤清在第二次世界大战期间创建并开始的。
时间序列分析代写
随机过程,是依赖于参数的一组随机变量的全体,参数通常是时间。 随机变量是随机现象的数量表现,其时间序列是一组按照时间发生先后顺序进行排列的数据点序列。通常一组时间序列的时间间隔为一恒定值(如1秒,5分钟,12小时,7天,1年),因此时间序列可以作为离散时间数据进行分析处理。研究时间序列数据的意义在于现实中,往往需要研究某个事物其随时间发展变化的规律。这就需要通过研究该事物过去发展的历史记录,以得到其自身发展的规律。
回归分析代写
多元回归分析渐进(Multiple Regression Analysis Asymptotics)属于计量经济学领域,主要是一种数学上的统计分析方法,可以分析复杂情况下各影响因素的数学关系,在自然科学、社会和经济学等多个领域内应用广泛。
MATLAB代写
MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中,其中问题和解决方案以熟悉的数学符号表示。典型用途包括:数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发,包括图形用户界面构建MATLAB 是一个交互式系统,其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题,尤其是那些具有矩阵和向量公式的问题,而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问,这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展,得到了许多用户的投入。在大学环境中,它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域,MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要,工具箱允许您学习和应用专业技术。工具箱是 MATLAB 函数(M 文件)的综合集合,可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。