Game Theory — non-cooperative games. - One Line Questions
1.
What is an 'information set' in a game of imperfect information? —
A collection of nodes where a player cannot distinguish which node they are at.
2.
A situation in a non-cooperative game where no player can improve their payoff by unilaterally changing their strategy is called: —
A Nash equilibrium.
3.
What is the 'discount factor' (delta) in the context of repeated games? —
A measure of how much players value future payoffs relative to current payoffs.
4.
In a two-player zero-sum game, if a saddle point exists, it corresponds to: —
A Nash equilibrium in pure strategies.
5.
What is the 'extensive form' of a game? —
A representation of the game as a decision tree, showing sequences of moves and information sets.
6.
In game theory, what does a 'strategy' represent for a player? —
A complete plan of action for every possible situation.
7.
Which of the following best describes the concept of 'correlated equilibrium'? —
A situation where players' strategies are correlated through an external mediator or signal.
8.
What is a 'mixed strategy' in game theory? —
A strategy that involves a combination of pure strategies with certain probabilities.
9.
What is a 'pure strategy' in game theory? —
A strategy where a player chooses a single action with certainty.
10.
What does the term 'payoff matrix' represent in a non-cooperative game? —
A table showing the payoffs for each player for every possible combination of strategies.
11.
The Minimax Theorem, by John von Neumann, applies to: —
Finite zero-sum games.
12.
If a game has a dominant strategy equilibrium, it implies that: —
All players have a unique best response to every possible strategy of the other players.
13.
The concept of 'repeated games' extends non-cooperative game theory by: —
Allowing the same game to be played multiple times.
14.
The 'Folk Theorem' in repeated games suggests that: —
Any feasible and individually rational payoff profile can be sustained as a Nash equilibrium in an infinitely repeated game.
15.
A game is considered to have 'perfect information' if: —
At every decision point, the player knows the complete history of the game.
16.
A 'Pareto improvement' is a change to a different outcome where: —
At least one player is better off, and no player is worse off.
17.
Which of the following is NOT a characteristic of non-cooperative games? —
Binding agreements are possible.
18.
In the Prisoner's Dilemma, the Nash equilibrium results in: —
Both players defecting and receiving a harsher sentence than if they had cooperated.
19.
The Prisoner's Dilemma is a classic example of a non-cooperative game. In this game, the dominant strategy for both players is typically: —
Defect
20.
A Nash equilibrium in mixed strategies exists when: —
Each player's mixed strategy is a best response to the other players' mixed strategies.
21.
In a game of imperfect information, a player's strategy must specify an action for: —
Every information set they might face.
22.
A strategy profile is subgame perfect if it represents a Nash equilibrium in: —
Every subgame of the original game.
23.
The concept of backward induction is used to find subgame perfect Nash equilibria in: —
Finite horizon sequential games.
24.
What does the concept of 'subgame perfection' apply to in non-cooperative game theory? —
Sequential games.
25.
What is the primary difference between cooperative and non-cooperative game theory? —
In cooperative games, binding agreements are possible; in non-cooperative games, they are not.
26.
Bayesian Nash Equilibrium is a solution concept for games with: —
Incomplete information.
27.
In non-cooperative game theory, the focus is on: —
Individual players' optimal strategies given the strategies of others.
28.
A 'threat' in a sequential game is credible if: —
It is in the best interest of the player making the threat to carry it out if the condition arises.
29.
What characterizes a 'dominant strategy' in a non-cooperative game? —
It yields the best payoff regardless of the other players' strategies.
30.
What is the 'maximin' strategy in a zero-sum game? —
Maximizing the minimum possible payoff.
31.
What is the 'minimax' strategy in a zero-sum game? —
Minimizing the maximum possible loss.
32.
A 'Pareto efficient' outcome is one where: —
No Pareto improvement is possible.
33.
Subgame perfection eliminates Nash equilibria that rely on: —
Non-credible threats.
34.
Which of the following is a common application of non-cooperative game theory? —
Oligopoly pricing decisions.
35.
Which of the following is a key assumption for applying the concept of Nash equilibrium? —
Players are rational and seek to maximize their own payoffs.
36.
In an infinitely repeated Prisoner's Dilemma, cooperation can be sustained as a Nash equilibrium if: —
Players are sufficiently patient (discount factor is high).
37.
What is the fundamental assumption of a non-cooperative game? —
Players act independently to maximize their own payoffs.
38.
Which solution concept is most appropriate for analyzing a situation where players might not fully trust each other's rationality? —
Rationalizability.
39.
A strategy profile is 'iteratively strictly dominated' if it can be eliminated by: —
Repeatedly removing strictly dominated strategies.
40.
The concept of 'rationalizability' is a refinement of Nash equilibrium that eliminates: —
Strategies that are not best responses to any belief about opponents' strategies.
41.
In a game of incomplete information, what does a player not know? —
The payoffs of other players.
42.
Which theorem guarantees the existence of at least one Nash equilibrium (possibly in mixed strategies) for any finite non-cooperative game? —
Nash's Existence Theorem
43.
What is the main challenge in analyzing games with a large number of players? —
The combinatorial explosion of strategy profiles and the difficulty of finding equilibria.
44.
Consider a sequential game. Backward induction starts by determining the optimal strategy at: —
The last decision nodes.
45.
A 'saddle point' in a payoff matrix of a zero-sum game is an entry that is: —
The minimum of its row and the maximum of its column.
46.
The 'normal form' of a game is equivalent to: —
The strategic form or payoff matrix.
47.
In a zero-sum game, what is the relationship between the payoffs of the players? —
The sum of the payoffs is always zero.
48.
In a game with imperfect information, players must form beliefs about: —
Which information set they are in.
49.
In a simultaneous move game, players choose their strategies: —
Without knowing the strategy chosen by the other player.