Welcome to the Economics Study


Welcome

Thank you for participating in this study. We expect this study to last about 90 minutes. Your earnings in this study will be paid to you in cash at the end of the session.

Throughout the experiment your identity will be kept totally private. Neither the experimenter nor the other participants will ever be able to tie you to your decisions.

The Experiment

In this experiment you will play a series of 20 games. In each of the 20 games you will be randomly paired with one other person for that game. Your partner in each game will change randomly throughout the study. You will never be able to predict which of the other participants in the room you are paired with for any game. Also, you will never play anyone more than one time.

In each game, you and your partner will make choices in two rounds. When the two rounds are over, your game will be complete. Then you will be randomly assigned a new partner and start a new game, again with two rounds.

You will repeat this process until you have completed a total of 20 games. Since each game will have two rounds, you will be in a total of 40 rounds over the course of the experiment.

In each game you will earn tokens. The tokens you earn in each game will be deposited in your Earnings Account. At the end of the study you will be paid $0.06 for every chip in your Earnings Account.

Each Round

Each game has two rounds. In each round you will decide between one of two options. You can either pull an amount X to yourself, or you can push an amount Y to your partner. In every decision, the amount you can push is three times the amount you can pull, that is, Y=3X. However, the values of X and Y will be changing from round to round.

Here is an example of a decision:

I choose to:       pull 10 tokens to myself, or
  push 30 tokens to the other player
 
My partner chooses to:       pull 10 tokens to him/herself, or
  push 30 tokens to the other player


There are four possible outcomes:

Possible Outcome 1: If you decide to pull 10 tokens to yourself and your partner decides to push 30 tokens to you, then your payoff is 40 tokens and your partner's payoff is 0 tokens.

Possible Outcome 2: If you decide to pull 10 tokens to yourself but instead your partner decides to pull 10 tokens for himself, then your payoff is 10 tokens and your partner's payoff is 10 tokens.

Possible Outcome 3: If you decide to push 30 tokens to your partner and your partner decides to push 30 tokens to you, then your payoff is 30 tokens and your partner's payoff is 30 tokens.

Possible Outcome 4: If you decide to push 30 tokens to your partner but instead your partner decides to pull 10 tokens to himself, then your payoff is 0 tokens and your partner's payoff is 40 tokens.

As you can see, your partner will be faced with the same decision as you. You will both make your decisions at the same time. That is, you must make your decision without knowing what your partner is deciding.

Each Game

Each time you are paired with a new partner you will play a 2-round game with that person. In each round you will make a decision like that above.

Here is an example of what a game could look like:

Round 1 Decision:

Round 1 - Make a Choice
I choose to:       pull 3 tokens to myself, or
  push 9 tokens to the other player
 
My partner chooses to:       pull 3 tokens to him/herself, or
  push 9 tokens to the other player
Round 2 - Next Round
I choose to:       pull 7 tokens to myself, or
  push 21 tokens to the other player
My partner chooses to:       pull 7 tokens to him/herself, or
  push 21 tokens to the other player


Notice that when you are asked to make your decision in the first round, you will also be able to see the decision to be made in the second round. This is shown in the grayed-out portion of the decision screen.

So, for example, suppose that in Round 1, you decide to push 9 tokens to your partner and your partner also decides to push 9 tokens to you. Then your payoff for the round would be 9 tokens and your partner's payoff would also be 9 tokens.

You will be able to see the results of your decision and your partner's decision before you make your decision for the second round. The screen you will see for your second-round decision looks like this:

Round 1 - Results
I choose to:       pull 3 tokens to myself, or
  push 9 tokens to the other player
My partner chooses to:       pull 3 tokens to him/herself, or
  push 9 tokens to the other player
Round 1 - Earnings
You: 0 + 9 = 9 Your Partner: 0 + 9 = 9
Round 2 - Make A Choice
I choose to:       pull 7 tokens to myself, or
  push 21 tokens to the other player
 
My partner chooses to:       pull 7 tokens to him/herself, or
  push 21 tokens to the other player


After seeing these results, you can go on to make a choice for Round 2. Suppose in this Round 2 you chose to push 21 tokens while your partner chose to pull 7. Then for this decision you will earning nothing while your partner earns 7 + 21 = 28 tokens.

This makes your total earnings for the game 9 + 0 = 9, while your partner's total earnings are 9 + 28 = 37. The results of this game will be reported to you like this:

Round 1 - Results
I choose to:       pull 3 tokens to myself, or
  push 9 tokens to the other player
My partner chooses to:       pull 3 tokens to him/herself, or
  push 9 tokens to the other player
Round 1 - Earnings
You: 0 + 9 = 9 Your Partner: 0 + 9 = 9
Round 2 - Make A Choice
I choose to:       pull 7 tokens to myself, or
  push 21 tokens to the other player
My partner chooses to:       pull 7 tokens to him/herself, or
  push 21 tokens to the other player
Round 2 - Earnings
You: 0 + 0 = 0 Your Partner: 7 + 21 = 28


That was the end of game 1.

Total Game Earnings
You: 9 tokens Your Partner: 37 tokens


When you finish viewing the results of the game, you can click . Then you will be randomly assigned a new partner from the others in the room and begin a new 2-round game.

How the Amounts to Pull and Push will Change

The amounts available to pull and push will change from round-to-round and from game-to-game. Here we explain how these values will be set.

For each decision, the number of tokens available to push will always be 3 times the number available to pull. For example, if you can pull 2 then you can push 6. Or, if you can pull 8, then you can push 24. If you can pull 10 then you can push 30.

In any decision the tokens you can pull will always be between 0 and 10. Since the push amounts are three times the pull amounts, the amount you can push will always be between 0 and 30.

There will also be a special way the pull and push amounts are determined within a game. In particular, the number of tokens you can pull in Round 1 plus the number you can pull in Round 2 will always equal 10. For example, if you can pull 4 in Round 1 then you can pull 6 in Round 2. Or, if you can pull 1 in Round 1 then you can pull 9 in Round 2. If you can pull 10 in Round 1, then you can pull 0 in Round 2.

Note that since the pull amounts in Round 1 and Round 2 always sum to 10, this means that the push amounts in the two rounds will always sum to 30. In other words, all games will have the same feature that the total amount to pull across the the two rounds is 10 and the total amount to push is 30. How games will differ is in how many push and pull tokens are allocated to Round 1 and how many to Round 2.

Finally, the push and pull amounts you see in any game will be drawn at random from all the possible pull and push amounts that meet these rules above. You will never know what values you will see in future games, but all possible values are equally likely.

So there are three things to remember about how the pull and push amounts are set:

  1. The push amounts are always 3 times the pull amounts.
  2. In each game the pull amount in Round 1 and the pull amount in Round 2 always sume to 10. As a result, the push amount in Round 1 and the push amount in Round 2 sum to 30.
  3. The values in each game are determined at random from all the values that meet rules (1) and (2)


Your History

If you want to look back at the history of play you have seen over the experiment, you can do this from any screen by hitting the button . This will show you your decisions, your partner's decision, and your earnings in each game.

Overview of the Experiment

As we are about to begin, keep these things in mind:

Thanks for participating. Good luck!