**Stopping rule:**
The number of interactions is limited by the budget of 16 000 CZK available for this project. Therefore, each assistant will keep visiting stores until he or she can no longer put together the set of change described in the Procedure section.
(We can visit maximum of 400 stores when the average value of a purchase is 40 CZK. However, because of cheating, we expect the number of visited stores to be lower.)
**Exclusion criteria:**
Each interaction deviating from the script described in the Procedure section will be marked as such by an assistant and excluded.
**Analysis:**
The effects of time of the day, probability of discovery, and of cashier’s and assistant’s gender on probability of cheating will be examined using a probit regression.
The difference between amounts of cheating in condition with lower and condition with higher probability of discovery will be examined using Mann-Whitney U test.
