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Games for social sciences experiments (Part 2)

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Activity 1Hi, my name is John.

I really like soccer. This is Peter, my best friend.

We’re like brothers.

Hi, I’m Peter. One of my favorite things to do is to

go to pop concerts.

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Activity 1Hm… I’ve bought 2 tickets to watch my favorite team play this Saturday evening. Let’s go together, Peter. I’m sure it’ll be fun!

Oh… What a coincidence! My favorite pop star is performing this Saturday evening too. I’ve even bought concert tickets. See, here’s the ticket I bought for you..

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Fill up the table belowTABLE A John and Peter’s happiness level on a scale of 1-4

John Peter

Scenario A: When John goes to the concert with PeterScenario B: When Peter goes to the match with JohnScenario C: When John goes to his match and Peter goes to his concertScenario D: When John goes to his concert and Peter goes to his match

1 ------------------------------2 ------------------------------ 3 --------------------------- --->4Very unhappy very happy

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Use information in Table A to fill in the matrix below

Peter goes to the concert

Peter goes to the match

John goes to the concert

( ___ , ___ ) ( ___ , ___ )

John goes to the match

( ___ , ___ ) ( ___ , ___ )

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Formalizing simultaneous games• Such a scenario where 2 people are making decisions at

the same time that can affect each other’s outcomes are known as simultaneous games

• Since there are 2 players- John and Peter, and each player has 2 choices. This is a 2-player, 2 by 2 game. (i.e. 2 choices by 2 choices)

• The 2 by 2 game has 4 different outcomes for each player.• This specific game we talked about is known as “Battle of

the sexes”.• Usually, simultaneous games are represented in a matrix

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ACTIVITY 2Luke, if you do well for your

exam, I will buy you a new iPhone.

Daddy, don’t worry. I know that if I study hard for my exam, I will do

well.

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ACTIVITY 2But that’s the question, will you bother to study hard for your exam or not?

Daddy, the question is if you will really buy me a new

iPhone if I do well or not? I know you prefer to save

money. You just say that to encourage me to study

hard…

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Formalizing sequential gamesDaddy and Luke’s happiness level on a scale of 1-3

Daddy Ah Boy

Scenario A: Luke studies, then Daddy buys phone

Scenario B: Luke studies, then Daddy goes back on his promise and doesn’t buy phoneScenario C: Luke doesn’t study, yet Daddy buys phone for himScenario D: Luke doesn’t study, and thus Daddy doesn’t buy phone for him

1 -------------------------------- ---------------2-------------------------------------------- --->3Very unhappy very happy

Formalized sequential game

Outcomes

Daddy’s decision to buy phone or not

Luke’s decision to study or notLuke

Daddy Daddy

Study Don’tStudy

Buy BuyDon’tBuy

( ____ , ____ )

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( ____ , ____ ) ( ____ , ____ ) ( ____ , ____ )

Don’tBuy

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Formalizing sequential games

• Such scenarios where 2 people are making decisions one after another are known as sequential games

• Since there are 2 players- Daddy and Luke, and each player has 2 choices. This is a 2-player, 2 by 2 game. (i.e. 2 choices by 2 choices)

• The 2 by 2 game has 4 different outcomes for each player.

• Sequential games are represented usually in an extensive form, also known as a tree diagram.