You are now in Part 1. In this part, you will be randomly assigned to the role of Person A or Person B. Each Person A will be randomly and anonymously paired with another participant in this session in the role of Person B. You will not learn the identity of the participant you are matched with during or after the study, and s/he will not learn your identity either during or after the study.

All participants (regardless of role) will be endowed with CZK 125 which is their payment for showing up for this study. Participants in the role of Person B will be endowed with an additional CZK 250 (bringing Person B’s total initial endowment to CZK 375). Part 1 will proceed as follows.

{{ if player.treatment == "T1_B" or player.treatment == "T2_B" }} Person A has no choice to make in this part. The computer will randomly select one of the two options below. Each option has the same likelihood of being selected. {{ else }} Person A has two options, A1 and A2, explained below: {{ endif }}

• A1: If this option is {{ if player.treatment == "T1_B" or player.treatment == "T2_B" }}randomly selected by the computer{{ else }}selected by Person A{{endif}}, then Person A and Person B will remain at their initial endowments. This means Person A will earn CZK 125 and Person B will earn CZK 375.
• A2: If this option is {{ if player.treatment == "T1_B" or player.treatment == "T2_B" }} randomly selected by the computer{{ else }}selected by Person A{{ endif }}, Person B’s choice will determine the earnings for both persons. This subsequent choice of Person B is explained below.

Person B’s choice: {{if player.treatment == "T1_B" or player.treatment == "T2_B"}} If the computer randomly selects A2, {{else}} If Person A chooses A2, {{endif}} then Person B can either:

{{ if player.treatment == "T1" or player.treatment == "T1_B" }}
• …take a part of Person A’s CZK 125 show-up fee, with the maximum amount that can be taken from Person A being CZK 75.
{{ endif }}
• …make no change to either of the endowments.
• …give Person A part of her/his CZK 375 endowment, with the maximum amount that can be given to Person A being CZK 250.

Thus, Person B’s choice (of transfer to Person A) can be anywhere from {{ if player.treatment == "T1" or player.treatment == "T1_B" }} –75 {{else}} 0 {{endif}} to +250, in increments of CZK 25. {{ if player.treatment == "T1" or player.treatment == "T1_B" }} Negative amounts will mean that Person B is taking that amount of Person A’s endowment, zero will represent no change and positive amounts will mean that Person B is giving Person A that amount from her/his endowment. {{else}} Zero will represent no change and positive amounts will mean that Person B is giving Person A that amount from her/his endowment. {{endif}}

We will ask Person B for her/his choice before Person B knows whether {{ if player.treatment == "T1_B" or player.treatment == "T2_B" }} the computer randomly selected A1 or A2. {{else}} Person A chose A1 or A2. {{endif}} If {{ if player.treatment == "T1_B" or player.treatment == "T2_B" }} the computer randomly selects A2, Person B’s choice will be implemented. {{else}} Person A chooses A2, Person B’s choice will be implemented. {{endif}} If {{ if player.treatment == "T1_B" or player.treatment == "T2_B" }} the computer randomly selects A1, Person B’s choice does not matter. {{else}} Person A chooses A1, Person B’s choice does not matter. {{endif}}

At the end of the study, Person A and Person B will learn about their earnings from Part 1.

The above instructions are summarized in the picture below: