Welcome to this experiment on decision making Centre for Ecological and Evolutionary Studies dept....
-
Upload
katerina-collard -
Category
Documents
-
view
214 -
download
0
Transcript of Welcome to this experiment on decision making Centre for Ecological and Evolutionary Studies dept....
Welcome to this experiment on decision making
Centre for Ecological and Evolutionary Studies
dept. of Theoretical Biology
General overview
• Instructions (ca. 15 minutes)• Receiving desk number• Going to lab• Experiment (max. 120 minutes)• Payment (outside laboratory)
• Earnings: 30 +/- 30 Euros
General overview
• Instructions (ca. 15 minutes)• Receiving desk number• Going to lab• Experiment (max. 120 minutes)• Payment (outside laboratory)
• Earnings: 30 +/- 30 Euros
In the lab…
• Instructions are on your desk• Quiz• Experiment itself• Questionnaire• Payment (outside of the lab…)
The experiment
• Do not talk inside the laboratory• You will earn money depending on your decisions
and the decisions of others• You get a show-up fee of XXX Euros• Payments are anonymous• You start out with XXX points• 10 points are worth 1 Euro
The experiment
• Lasts for 10 periods• Each period you will be part of a group
• Randomly assigned• Anonymous• You get a ‘symbol’
•#, $, %, etc
Interacting in your group
• ‘Contribution game’• At least 1 round• New round will start with a 80% chance• Period ends with a 20% chance• Initially, your group will consist of 3 players
The contribution game
• Each round, you can contribute to a project• Costs: 4 points
• Contributions are made simultaneously• The revenues of the project are the sum of the
group’s investments x 1.5• Equally split among the group members
• Both contributors and non-contibutors
The contribution game: example I
• Example 1: all three group members contribute • Cost per player = 4 points
• Total contributions to the project• 3 x 4 = 12 points
• Project’s revenue• 12 x 1.5 = 18 points
• All group members get 6 points• Earnings in this round: 2 points for all group
members
The contribution game: example II
• Other group members contribute, you do NOT contribute • Cost for you = 0 points
• Total contributions to the project• 2 x 4 = 8 points
• Project’s revenue• 8 x 1.5 = 12 points
• Your group-mates earn 0 points• You earn in this round: 3 points
Hiring a ‘supervisor’
• Before the contribution game starts• Your group can decide to hire a supervisor
• Rigorous supervisor• Lenient supervisor• No supervisor
• Supervisor is hired for 1 period• Supervisor is a computer program
Hiring a ‘supervisor’
• Each round of the period that the supervisor is hired
• Non-contributors will NOT get revenues with chance• Rigorous supervisor 100%• Lenient supervisor 50%• No supervisor 0%
• Supervisor is hired for 1 period
Hiring a ‘supervisor’
• Each round of the period that the supervisor is hired
• Non-contributors will NOT get revenues with chance• Rigorous supervisor 100% cost: 2 points• Lenient supervisor 50% cost: 1 point• No supervisor 0% cost: 0 points
• Each round of that period, all group members have costs for the supervision
Hiring a ‘supervisor’
• Which supervisor is hired, depends on majority voting
• Before voting, you can discuss which supervisor to hire in a chat box
• If none of the options gets the majority, the computer program will select a random option
Hiring a ‘supervisor’: example
• You are in a group with 2 others• You hired a ‘lenient supervisor’ for this period
• Cost: 1 point per player per round • One of your group-mates (‘#’) contributes• The other (‘$’) does not contribute
• What are the earnings of the players in this round if you do (not) contribute?
Hiring a ‘supervisor’: example
• What are the earnings of the players in this round if you do (not) contribute?
Your decision
Total amount invested
Project revenue
Your earnings
Earnings of ‘#’
Earnings of ‘$’
Contribute 8 (2x4)
12 (8x1.5)
–1(12/3 – 4 – 1)
–1 (12/3–4–1)
3 or –1(12/3–1) or (12/3
– 1 – 12/3)
Do not contribute
4(1x4)
6(4 x 1.5)
1 or –1(6/3–1) or (6/3 –
1 – 6/3)
–1 (6/3-4-1)
1 or –1(6/3–1) or (6/3 –
1 – 6/3)
50-50 chance
Recapitulation
• As far as we have seen, a period looks like this:1. Chatting2. Voting for hiring a supervisor3. Playing the ‘contribution game’ for a number
of rounds• The number of rounds per period
is equal for all groups
Group growth, splitting and elimination
• At the end of each period, average earnings of the groups are compared
Group growth, splitting and elimination
• At the end of each period, average earnings of the groups are compared
• One group will have the highest average
Group growth, splitting and elimination
• At the end of each period, average earnings of the groups are compared
• This group will grow, two participants are added to this group
Group growth, splitting and elimination
• At the end of each period, average earnings of the groups are compared
• The next period will start, one group being larger
Group growth, splitting and elimination
• After a number of growth events, it may occur that a group of 5 players has the highest average earnings
Group growth, splitting and elimination
• After a number of growth events, it may occur that a group of 5 players has the highest average earnings
• In this case, the group with the lowest average earnings will be eliminated
Group growth, splitting and elimination
• After a number of growth events, it may occur that a group of 5 players has the highest average earnings
• In this case, the group with the lowest average earnings will be eliminated
•Questionnaire
•Payment
Group growth, splitting and elimination
• After a number of growth events, it may occur that a group of 5 players has the highest average earnings
• One participant is added to the this group
Group growth, splitting and elimination
• After a number of growth events, it may occur that a group of 5 players has the highest average earnings
• The group splits in two
Group growth, splitting and elimination
• After a number of growth events, it may occur that a group of 5 players has the highest average earnings
• A new period starts
Summary of a period
1. Hiring a supervisor
2. Playing contribution game
(a number of times)
3. Growth, splitting and elimination of
groups
• In total, the session will last for 10 periods
Session end: questionnaire & payment
• After 10 periods, the experiment ends• You are asked to fill out a few questions about
your personal background• Please remain seated until your desk number
is called• You will be paid in cash individually and
anonymously
Questions ?