Appendix: Experimental Instructions

The following is the verbatim translation (from Spanish into English) of the experimental instructions administered to subjects (the Spanish original is available from the authors upon request).

Script for the experimental sessions

• Mark starting time


1. Introduction

• Start thanking for the participation.

• Show disposition to clarify any doubt or question.

• Give payment of $ 50 for agreeing to participate without any commitment.

• Indicate that participation is voluntary at all times.

• Inform that we are members of a research center at a University institution.

• Inform that we are not members of the Government or any political party.

• Inform that the study is only for academic purpose.

• Warn that the questions and their answers will not compromise their rights.

• Ensure that we guarantee the confidentiality of their responses.

• Point out that the questions have no correct or incorrect response.

• Point out that we are only interested in their decisions.

• Describe the study: This is a study about how people make decisions with money.

• Show the activity book, with which they can earn an additional amount of money.

• Ask whether they have any questions.

• Consent question: Can we start?


2. Starting the activity book and warning about the comprehension of the instructions

• Show the activity book.

• Inform that it is of our interest that they understand the instructions.

• Warn them that they can stop us if there is something unclear from the explanation.


3. General description of the activity, of how the activity to be paid for will be chosen, and of how the payment will be made


In this activity you will make decisions that involve other participants. This activity is done in pairs. The result of this activity will depend on decisions made separately and the decisions made by you and the other three participants of the study, whom we will call: B1, B2 and B3.

You will never know who these participants are. They will never know who you are. You may know some characteristics of these people before making your decision. To know some of these features (if desired) you may purchase them using the 50 pesos we gave you at the start. You will also know the decision made by any of these participants. However, you will know the latter at the end of the study, when you have already made all your decisions.

• Go to the end of the book and show the three boxes of decision.


4. Method of payment

To pay you for this activity, one of your decisions will be randomly chosen using a dice. After you finish making your decisions, we will throw a dice:

1) If the number is 1 or 2, we will choose for your payment your decision related to participant B1.

2) If the number is 3 or 4, we will choose for your payment your decision related to participant B2.

3) If the number is 5 or 6, we will choose for your payment your decision related to participant B3.

[Check that the subject understood the procedure by asking the following question: For example, let's throw the dice. The number that appeared is _ [The participant's answer], therefore the decision chosen for your payoff will be the one you made related to participant _ [The participant's answer.]

Any side of the dice can occur. You will not know what the other participants' decisions are before throwing the dice.

Make your decision regarding each subject as if it is the one you are going to be paid for. Thus, if this participant is selected, you will have taken the decision that has seemed better. There is no right or wrong answer.

Do you have any question?

[If he/she has questions, explain again.]

[Explain using diagrams in pages 2 and 3.]


Person A

In this activity you are going to be a person A, and each of the other participants will be identified as persons B1, B2 and B3.

This page is only an example, but it is equal to the one in which you will have to mark your responses. We will begin our example explaining the activity with a person who we call simply person B.

You will start with $300 pesos that our study is giving to you to decide how much of that money you want to send to person B. The money you send is multiplied by three, so that person B will receive three times the amount that you send. That is, for every $1 peso you send to person B, the study will give $2 additional pesos and, consequently, person B will receive $3 in total.

Person B may return to you some, all or nothing of the money received, but the money that person B returns to you will not be multiplied.

Thus, you will win what you have saved from the initial $300 plus what person B had decided to send you back.

Do you have any questions?

Now I am going to explain to you how you will tell us your answer and how we will know the response of person B. Here we have seven pictures, representing seven quantities you can send to person B.

[Show each picture and explain each of them.]

The first possibility is that you save the $300 pesos and send nothing to person B. If you choose this option, person B would receive nothing and could therefore not return anything to you.

The second option that you have is to stay with $250 and send $50 to your partner. In that case, person B would receive $150 ($50 x 3) and your income would be $250 plus what person B decides to return to you.

[Continue explaining likewise all options.]

[Speed and detail explanation depend on cognitive abilities of the participant.]

What we will ask you to do is to decide how much money you want to send to your partner ($ 0, $ 50, $ 100, $ 150, $ 200, $ 250 or $ 300).

When sending money to different partners, the quantities that you send to each partner B1, B2 or B3 can be equal or different. It is your decision.

To indicate your decision of how much you have decided to send to each partner you must enclose in a circle the corresponding answer. You must choose only one option; the one you like the best.

[Make a graphical demonstration.]

For example, suppose that I am a person A (like you) and I want to send $100 to person B. Then I would circle this option.

It is very important that you notice that the money you earn for this activity will depend on how much money you keep and on how much money your partner, person B, will return to you.

Now, how are we going to know who your partner is and how much money he has returned?

I brought with me a list with the decisions of other people who have already participated in the study. These people played the role of person B. When you finish answering and we select the corresponding partner, then I will pull out the list and look for the decision of the selected person.

You will not know what the responses from those people are before you make your own decisions; you will not know who your final partner is because the person's name is not mentioned in the list.

Once you know the chosen partner we will open the list to see how much money he/she returned.

[Give the explanation using the corresponding pages.]

And how can we know what he/she responded? This page is an example of the sheet that person B responded. The page has seven amounts he/ she responded and they correspond to the seven drawings you have on your answer sheet.

Just as you do not know at this time what your partner decided, when person B responded he/she didn't know how much money you had sent him/her. Then person B had to say, for each quantity that you can send him/her, how much money he/she would return. Thus, for any amount you decide to send, we will know how much money will be returned.

[Make a graphical explanation.]

For example, suppose that I am a person B and that I say: "If my partner, person A, does not send me anything, then I don't receive anything and I cannot return anything" (This is why $0 is already written with a gray circle.)

Then I would go to the next option and would say "If person A sends me $50, I would receive $150 ($ 50 x 3) and then return you, say, $ 100".

Then I would go to the next option and would say "If person A sends me $ 100, I would receive $300 ($ 100 x 3) and then return you, say, $ 200".

[Go ahead with the example, using the quantities $ 200, $ 300 and $ 400 for the following three decisions.]

Now, imagine that you sent to person B the amount of $100 used in the example, and that this person is selected for your payment. Let's imagine that we open the list and see that person B responded as in this example.

What would have happened? How much money would your partner have returned to you?

If you look carefully, this person B said that if person A sent him $100 he or she would return $200. Then how much would you win? $400: the $200 you saved originally plus the $200 that person B returned.

And how much does person B win? $100: $300 that he/she received minus the $200 that returned (remember that person B had received $300, because the $100 that person A sent would have been multiplied by 3).

Do you have any questions? Remember that person B can return what he or she wants: some, all or nothing of what you sent.

[Write new examples on the same pages.]

[The second example is mandatory, but others depend on whether the participant seems to need them.]

For example, person B might return nothing. [Explain what would happen.] Or he/she could have returned $0, $50, $100, $150, $200, etc. Is it clear?

Now, remember that these are only examples. You can choose to send to any of the partners (participants B1, B2 and B3) the amount you prefer within these seven options; and your partners (participants B1, B2 and B3) can give you back what they want to.

[Switch to the worksheet of partners' features.]


Buying features' information

Before making your decisions you may know some information about some features of these people. You can choose up to five characteristics of them. The features that you may know of these people are the following: his/her age, gender, whether he/she is married, his/her level of education, his/her employment status, his/her income, whether he/she has any of the following goods: phone, cell phone, refrigerator, heating gas, television, video or DVD player, washing machine, vehicle, microwave oven, Sky or cable; whether owns his/her home; whether he/she has a bank account; whether he/she helps the cooperative; whether he/she lives or not in the same town.

If you are interested in knowing some of these features, you simply tell me and I will give you this information for each of your partners. Each feature has a cost of 10 pesos, which may be paid using the 50 pesos we gave you at the beginning. You can purchase 5, 4, 3, 2, 1, or 0 characteristics of your partners.

For example, if you decide to know his/her gender, I will give you the information whether the person B1 is a woman or a man, whether the person B2 is a woman or a man and whether the person B3 is a woman or a man. This information will cost 10 pesos. Similarly, any other information you want to know will cost 10 pesos.

I am going to ask, before we move on, to make your decisions marking with an X the features you want to know about these people.

[Given the chosen features, fill the characteristics of these people sheet.]

We will then turn the page and I am going to ask you to enclose the amount of money you want to send to each of your partners in a circle. Let's start with the B1 couple. We will then move to the B2 and finally the B3 couple. Remember that you can only choose one for each pair.

[Perform the payment procedure.]

We now come to the payment procedure.

• Mark the end time


Source: Authors' own elaboration.