Experimental Design
The experiment involves 9 treatments in a 3x3 between subjects design. The experiment extends the experiments reported in Altmann et al. (2019). For further details about the tasks, treatments, and outcomes please refer to experimental design section of Altmann et al. (2019).
In each treatment, subjects are confronted with two tasks, denoted as “Background Task” and “Decision Task”, which they solve simultaneously.
As background task, subjects have to memorize 7-digit numbers. At the beginning of each round of the experiment, a new number is displayed for 10 seconds on subjects’ screens. Subsequently, the number disappears and subjects have to keep it in mind. After another 30 seconds, subjects have to type in the memorized number in an input field on their screen. In the 30 seconds between memorizing the number and entering the memorized number, subjects can work on the decision task. As decision task, subjects face three summations, each of which consists of six addends. Their task is to decide which of the three options yields the highest sum.
The first treatment dimensions varies the monetary incentives for completing the tasks correctly:
1) In treatments with a “40/10” incentive, subjects earn € 0.40 [€ 0.10] if they correctly solve the background task [decision task] in a given round.
2) In treatments with a “40/20” incentive, subjects earn € 0.40 [€ 0.20] if they correctly solve the background task [decision task] in a given round.
3) In treatments with a “40/40” incentive, subjects earn € 0.40 [€ 0.40] if they correctly solve the background task [decision task] in a given round.
The second treatment dimension varies how the decision task is displayed to subjects:
1) In treatments involving the “Baseline” environment, subjects can access the decision task by holding a button on the keyboard pressed. In addition, the decision task features a default option that is implemented if subjects do not make an active decision. In particular, in each round, one option of the decision task is randomly selected and displayed as the default choice.
2) In treatments involving the “Directed Attention” environment, the decision task is permanently displayed on subjects’ screens during the 30 seconds in which they keep the number for the background task in mind. Similar to the “Baseline” environment, the decision task in the Directed Attention environment involves a randomly selected default option.
3) In treatments involving the “Active Choice” environment, the decision task is permanently displayed on subjects’ screens during the 30 seconds in which they keep the number for the background task in mind. Moreover, the decision task in the Active Choice environment involves no default.
Subjects participate in only 1 treatment cell (defined by an “incentive” / “decision environment” combination). In the main part of the experiment, subjects play 20 rounds of the respective treatment. The tasks, numbers, defaults, and their order are identical across all subjects and treatments.
Before participating in the main experiment, subjects participate in two additional parts of the experiments in which they only face the background task (Part 1) and decision task (Part 2), respectively. In part 1, subjects play 10 rounds in which they have to memorize numbers of varying difficulty (between 7 to 8 digits).They receive € 0.1 per correctly solved task. In part 2, subjects play 10 rounds of the decision task. They receive € 0.1 per correctly solved task.
References:
Altmann, S., Grunewald, A., & Radbruch, J. (2019). Passive Choices and Cognitive Spillovers. IZA Discussion Paper No. 12337