Theory of SPE

Face
Timage
（个人形象）
Positive face (积极面子）
Negative face （消极面子）
Positive face
Positive face: the positive consistent self-image that people have and want to be appreciated and approved of by at least some other people.
• ( 2 ) “今晚我可以借用一下你的唱机吗 ? ”一个人对他的邻 居说道。“当然可以。你也想听 听 音 乐 吗 ? ” “ 不 , ” 他 回 答道, “今晚我想安安静静地休息一下。”
2 .威胁听话人的积极面子而产生的幽默
• ( 3 ) 妻子问丈夫: “你是喜欢我的温柔可爱呢, 还是我的聪 明美丽?”丈夫答: “我就喜欢你的这种幽默感! ”
威胁说话人的消极面子
7：麻 雀 问 乌 鸦 : “你 是什 么 鸟 ? ” 乌 鸦 说 : “我 是 凤凰 。” 麻 雀 : “有 你 这 么 黑 的 凤凰 ? ” 乌 鸦 白 了 麻 雀 一 眼 说 :“我是烧锅炉的凤凰! ”
损害说话人的积极面子
8：一 天 回 家 , 四 个 孩 子正 在 吵 闹 。 太 太 见 我 回 来 很 高兴 : “你 终 于 回 来 了 。 ” 我 以 为孩 子 们 怕 我 。 谁 知 太 太 接 着 说 :“家 中 只 有 你 听 话 , 乖 ! 快 去 帮我买袋盐。”
Thank you!
What is politeness?
• Politeness is showing awareness of another person’s face.(Brown and Levinson)

1Lecture 10Applications of SPEReadings•Watson: Strategy_ An introduction to game theory–1rd ed: Ch15-Ch17; 3rd ed: Ch15-Ch17.2•Exercises: Ch15.4, Ch16.4(a)-(c)A Game: Cash in A Hat(Toy Version of Lender and Borrower)☐Player 1 can put $0, $1, or $3 in a hat☐The hat is passed to player 2☐Player 2 can either “match”(i.e. add the same amount) or take the cash☐Payoffs:☐Player 1: 0→0; 1→double if match, -1 if not;3→double if match, -3 if not.☐Player 2: 1.5 if match 1; 2 if match 3; the $ in thehat if takes.4Sequential Move Game☐Player 2 knows player 1’s choice before 2 chooses;☐Player 1 knows that this will be the case.5A Game: Cash in A Hat60, 01, 1.5-1, 13, 2-3, 3131-13-3122Backward Induction7Look forward, work back.0, 01, 1.5-1, 13, 2-3, 3131-13-3122Moral Hazard☐Moral hazard: agent has incentives to do things that are bad for the principal.☐Example in “cash in a hat”: kept the size of loan/project small to reduce the temptation to cheat.8Incentive Design☐Change contract to give incentives not to shirk☐“A small share of a large pie” can be bigger than “a large share of a small pie”.9Incentive Design100, 01, 1.5-1, 11.9, 3.1-3, 3131-13-3122Incentive Contracts☐Piece rates☐Share cropping☐Collateral☐Subtract house from run away payoffs☐Lowers payoffs to borrower at some tree point,yet make the borrower better off☐Change the choices of others in a way that helps you11Collateral120, 01, 1.5-1, 1(-house)3, 2-3, 3(-house)131-13-3122Commitment Strategy☐Getting rid of choices can make me better off ☐Commitment: to have fewer options and itchanges the behavior of others☐Knowledge: the other players must know thesituation changed13Stackelberg’s Duopoly GameConstant Unit Cost and Linear Inverse Demand ☐Players ：the two firms (a leader and a follower)；☐Timing:☐Firm 1 chooses a quantity ；☐Firm 2 observes and then chooses a quantity ;☐Payoff ：Each firm’s payoff is represented by its profit.10q ≥1q 20q ≥14Basic Assumptions☐Constant unit cost ：☐Linear inverse demand function ：☐Assume ：() for all i i i iC q cq q =() if , 0 if iQ Q P Q Q q Q ααα-≤⎧==⎨>⎩∑c α<15Lessons☐Commitment: sunk costs can help☐Spy or having more information can hurt you ☐Key: the other players knew you had moreinformation☐Reason: it can lead other players to take actionsthat hurt you☐First-mover advantage18First-mover advantage☐Yes sometimes: Stackelberg☐But not always —Second mover advantage ☐Rock, paper, scissors☐Information here is helpful☐Sometimes neither first nor second mover advantage ☐Divide a cake with your sibling: I split, you choose.☐It can be first or second mover advantage within the same game depending on setup☐The game of Nim19Chain-store Paradox☐试想一个博弈：在每个省会城市，都有麦当劳连锁店，每个城市都有一个挑战者想进入该行业。

九分达人theory or practice Theory or Practice: Which is More Important in Mastery?Introduction:In the pursuit of mastering a skill or field, individuals often contemplate the balance between theory and practice. While theory provides the foundation, practical application tests and solidifies knowledge. Both theory and practice play significant roles in mastery. However, the question remains: which is more important? This essay will delve into this debate, exploring the importance of both theory and practice in various scenarios.Body:1. The Significance of Theory:Theory serves as the cornerstone of any field of knowledge. It provides the conceptual framework andunderstanding necessary for practical application. For instance, in scientific fields, theories such as relativity and quantum mechanics lay the groundwork for experimentation and technological advancements. Similarly, in academic disciplines like history and literature, theories provide critical analysis tools for interpreting and analyzing texts and events. Thus, theory is essential for individuals to grasp the underlying principles and concepts of a subject.2. The Power of Practical Application:While theory is crucial, practice is equally important in mastering a skill or field. Practical application allows individuals to put theory into action, enhancing their understanding and refining their abilities. Take a musical instrument, for example. Understand the theoretical aspects of playing a guitar, such as chords and scales, is essential. However, it is through consistent practice that individuals can develop muscle memory, speed, and creativity in playing.Only through practical application can individuals truly internalize and excel in a skill.3. Complementary Nature of Theory and Practice:Theory and practice are not mutually exclusive; instead, they work in tandem to facilitate mastery. Theoretical knowledge forms the foundation, guiding individuals in their practical endeavors. Conversely, practical experience enriches theoretical knowledge, deepening understanding by revealing the complexities and nuances that theory alone cannot capture. Achieving mastery requires a continuous cycle of learning, applying, and reflecting. As Albert Einstein once said, "The only source of knowledge is experience." Theory and practice are symbiotic, with each enhancing and reinforcing the other.4. The Balance between Theory and Practice:Finding the optimal balance between theory and practiceis essential for mastery. In some fields, such as academia orresearch, theory might hold more weight due to the need for deep understanding and original thinking. On the other hand, practical skills, like carpentry or cooking, requireextensive practice to refine dexterity and technique. In reality, the balance might vary depending on the context and individual goals. For example, an individual aspiring to become a successful entrepreneur may require a solidtheoretical understanding of business concepts and strategies. However, they must also gain practical experience bylaunching and operating their own ventures.5. The Importance of Context:The importance of theory and practice can also be influenced by the context in which they are applied. Incertain situations, theory might be prized more heavily than practice. For example, in academic settings, deep theoretical knowledge and critical thinking skills are often valued above practical proficiency. However, in the professional world,practical skills and experience are often considered more important for career success. Different fields and industries place varying degrees of emphasis on theory and practice, making it essential to adapt accordingly.Conclusion:In the quest for mastery, both theory and practice play significant roles. Theory provides the foundation, enabling individuals to understand fundamental concepts and principles. Meanwhile, practice transforms that theoretical knowledgeinto real-world skills through repetition, adaptation, and refinement. The ideal approach is to strike a balance between theory and practice, recognizing their complementary nature and leveraging them according to the context and goals. Ultimately, mastery lies in the integration of theory and practice, with each enriching the other in a continuous cycle of growth and development.。

Game Theory 101 IntroductionDefinition: the study of strategically interdependent behavior. Chapter 1 The BasicsChapter 2 Extensive Form GamesChapter 3 Advanced Strategic Form GamesA dominant strategy is a strategy that leads to better outcomes for a player than other available strategies(while taking into account the strategies that other players can use).Dominant strategies can be strictly dominantor weakly dominant:1. A strategy is strictly (or strongly) dominant ifit leads to better outcomes than alternative strategies.2. A strategy is weakly dominant if it leads to equal or better outcomes than alternative strategies.A dominated strategy is a strategy that leads to worse outcomes for a player than other available strategies (while taking into account the strategies that other players can use).Dominated strategies can be strictly dominated or weakly dominated:1. A strategy is strictly (or strongly) dominated if it leadsto worse outcomes than alternative strategies.2. A strategy is weakly dominated if it leads to equal orworse outcomes than alternative strategies.Chapter 1The Prisoner’s dilemma:有关于囚徒困境的一些想法重点在于最终的结果选择往往不是对整体最好的选择，即：（-1，-1）> (-8, -8)但是双方都选择了(-8, -8)Dominant strategies 占优策略V.S Dominated strategies被占优策略Strict DominanceStrategy x strictly dominates strategy y for a player if x generates a greater payoff than y regardless of Iterated Elimination of Strictly Dominated Strategy IESDS逐步删减，一条一条删掉If you ever see a strictly dominated strategy,eliminate it immediately.Oder does not matter.If ISEDS leads to a single outcome, you willarraive at that outcome whether you eliminatestrategy #1 or strategy #2 first.The Stag Hunt纳什均衡不一定是对组合最优的，但是每个选择都是均衡稳定的。