Ben Polak is the William C. Brainard Professor of Economics and Professor of Management at Yale University. His work spans decision theory, game theory, and economic history. — Yale SOM: Benjamin Polak.

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On the Fundamentals of Game Theory

  1. Strategic situations are defined by interdependence: what happens to you depends partly on other people’s actions, not only your own. — Open Yale Courses: Lecture 1
  2. Analyze a game by making the players’ available actions and the objectives reflected in their payoffs explicit before predicting behavior. — Open Yale Courses: Lecture 1
  3. Game theory clarifies the consequences of specified objectives; it does not choose those objectives for the players. — Open Yale Courses: Lecture 1
  4. Use game theory both to make better strategic choices and to predict how people or organizations behave in strategic settings. — Open Yale Courses: Game Theory

On Rationality and Dominance

  1. Do not choose a strictly dominated strategy: another available strategy gives you a better payoff regardless of what others do. — Open Yale Courses: Lecture 1
  2. Weak dominance is more delicate: one strategy does at least as well in every case and strictly better in some cases. — Open Yale Courses: Lecture 2
  3. Iterative deletion can simplify a game: after removing dominated strategies, reassess the reduced game because further strategies may become dominated. — Open Yale Courses: Lecture 3
  4. Individual rationality need not produce a collectively good outcome; the Prisoner’s Dilemma is the canonical warning. — Open Yale Courses: Lecture 1
  5. Price competition illustrates a Prisoner’s-Dilemma incentive: each firm may want to undercut even though mutual restraint would be better for both. — Open Yale Courses: Lecture 1

On Nash Equilibrium

  1. A Nash equilibrium is a profile of choices in which every player’s choice is a best response to the others’ choices. — Open Yale Courses: Lecture 6
  2. Dominance can eliminate some choices before equilibrium analysis, but Nash equilibrium still requires checking each player’s best response. — Open Yale Courses: Lecture 3
  3. For a continuous choice problem, a best-response function can be found by maximizing the player’s payoff for each possible choice of the other player. — Open Yale Courses: Lecture 6
  4. A best response depends on beliefs about the other players’ choices; Polak uses this to move beyond iterative deletion of dominated strategies. — Open Yale Courses: Lecture 3

On Different Types of Games and Strategies

  1. In a sequential game, backward induction starts at the final decision points and works back through the game tree. — Open Yale Courses: Lecture 13
  2. Mixed strategies model deliberate randomization, with applications in sports and in audit or enforcement settings. — Open Yale Courses: Lecture 10
  3. Evolutionary stability studies whether a strategy can persist in a population when challenged by alternatives. — Open Yale Courses: Lecture 11
  4. The hawk–dove model makes the trade-off between the value of a contested resource and the cost of fighting explicit. — Open Yale Courses: Lecture 12
  5. Imperfect-information games use information sets to represent decision points a player cannot distinguish. — Open Yale Courses: Lecture 18
  6. Repeated interaction can make cooperation sustainable when future rewards and credible punishment strategies change current incentives. — Open Yale Courses: Lecture 22
  7. Asymmetric-information models examine strategic choices when players have different information, including signaling and adverse-selection problems. — Open Yale Courses: Game Theory

On Strategic Thinking and Decision Making

  1. Strategic thinking requires modeling other players’ incentives and anticipating the choices those incentives make attractive. — Open Yale Courses: Lecture 1
  2. Higher-order reasoning, as in the two-thirds-average game, depends on what you expect others to expect about rationality. — Open Yale Courses: Lecture 2
  3. In timing games such as a duel, the strategic question may be when to act rather than which action to take. — Open Yale Courses: Lecture 16
  4. In Polak’s duel example, waiting improves a player's position when the opponent is not about to act; acting early is not always better. — Open Yale Courses: Lecture 16
  5. Commitment works only when it changes the other side’s incentives and makes a future action credible. — Open Yale Courses: Lecture 13

On the Broader Applications and Implications of Game Theory

  1. Game theory models both competitive and cooperative economic settings; Cournot competition is one course example of strategic interaction between firms. — Open Yale Courses: Lecture 6
  2. Iterative deletion can be used to analyze policy-position competition; the course applies it to the median-voter theorem. — Open Yale Courses: Lecture 3
  3. Game theory can be applied to evolution, including strategic behavior in biological populations. — Open Yale Courses: Lecture 1
  4. The course identifies law as an important application area for game-theoretic reasoning. — Open Yale Courses: Lecture 1

Learnings from His Research and Academic Work

  1. Ben Polak’s Yale profile identifies work across decision theory, game theory, and economic history. — Yale SOM: Benjamin Polak
  2. Polak’s work studies economic agents with goals richer than those captured in traditional models. — Yale SOM: Benjamin Polak
  3. His game-theory research includes foundational theoretical work on common knowledge. — Yale SOM: Benjamin Polak
  4. His Yale profile also notes contributions to the theory of repeated games with asymmetric information. — Yale SOM: Benjamin Polak
  5. Other listed research interests include economic inequality and how individuals respond to uncertainty. — Yale SOM: Benjamin Polak
  6. His Yale profile describes an empirical project on industrial organization during England’s Industrial Revolution. — Yale SOM: Benjamin Polak