# Repeated Prisoner’s Dilemma Tournament

I have played this with my classes and although not in the CIE A2 syllabus, found it useful to go into greater detail as to the strategies available.

Robert Axelrod used an experimental method – the indefinitely repeated PD tournament – to investigate a series of questions: Can a cooperative strategy gain a foothold in a population of rational egoists? Can it survive better than its uncooperative rivals? Can it resist invasion and eventually dominate the system? Contestants submitted computer programs that select an action, Cooperate or Defect, in each round of the game, and each entry was matched against every other, itself, and a control, RANDOM.

Prisoner’s Dilemma in the classroom.

This game can be played over as many rounds as you wish and played between two players in the classroom environment. The pay offs shown – Win = 3 or 5, Lose = 0 or 1

Below shows the first 14 rounds of a 100 round PD game between John and Kate that includes the comments that were apparently written after each player had decided on strategy in that particular game, but before the other player’s choice was known.

Strategies – see below

• D (ALWAYS DEFECT): Defect on every move.
• C (ALWAYS COOPERATE): Cooperate on every move.
• T (GRIM – TRIGGER): Cooperate on the first move, then cooperate after the other cooperates. If the other defects, then defect forever.
• TFT (TIT FOR TAT) cooperates in the first round, and then does whatever the opponent did in the previous round.
• PAVLOV: 1st round, Cooperate. Thereafter if you win use the same action on next round. If you lose switch to the other action.

PAVLOV v M5. Time-average payoffs can be calculated because any pair will achieve cycles, since each player takes as input only the actions in the previous period. Here there is an average of 2 per player per cycle.

# Economics Speed Essay Game

Rationale

• This is a fun game to help students who hate writing or revising essays/short answers for IGCSE, AS Paper 2 and A2 Paper 4 .
• I see this as both a formative tool that can be used in normal teaching as well as a revision exercise in Term 4.
• I am sure you will have your own ideas and I would be interested as to how you adapt and modify to meet the nature of your individual teaching style and syllabus.

Brainstorming key ideas related to the essay (Term 4)

• Divide class into 2,4 or 6 groups of approx 4 students. You may try to mix abilities or academically stream depending on your cohort. Each team to elect an ‘Examiner’. This person will rotate and change with each game.
• Choose an essay (Most Eco essays have two parts A & B). Half the teams will start with essay A, while half start with essay B.
• Prior to the essay game you may wish to revise the topic and / or give students time as a team to do so.
• The teams get 2 mins to try to name as many mark points as they can. The Examiner cannot help the teams but can simply tick and confirm when they get a mark point.
• The Bonus round! At the end of 2 minutes the Examiner A swaps with Examiner B. Hence all teams have seen both essays. The new team is read the question as well as the mark points already gained by the previous team. Any extra mark points that they brainstorm are bonus points. (You may wish to give these double value!)
• Marks are collated both as a team of 4 students as well as a Super Team of 8 students i.e. the 2 teams that work together on the same essays A & B.
• Team Points can me collated over a lesson or a term. You may wish to offer a prize to the best team and/ or the best Super Team.

Essay Plan (Term 2)

• In pairs, they have 2 mins to plan a logical chain of thought that links the mark points they individually understand.
• Do not encourage them to use point that they do not understand. Remember that aiming for B/C grades do not need full marks.

Writing a draft essay (Term 1)

• Students have 1 min in silence to revise the essay.
• Students have 4 min in silence to revise the essay.
• Student pairs then mark each others essays.

# Economics games for the classroom

Following on from Geoff Riley’s blog post (see below) on the Tutor2u site here are the games that he was alluding to.

In this blog I am reprising an article produced by our good friend Mark Johnston from New Zealand in an early edition of the now discontinued Latte Magazine(2007). I am doing so because I know that many colleagues are interested in trying some experimental games with their students for example when teaching game theory, behavioural economics and the provision of public goods.

Click the link for the games in pdf format from the Latte Magazine
winter07-economicsgames

Here is another that I have used recently on Oligopolies.
Oligopoly Game