The experiment has four parts. Participants receive sperate instructions for each part. The instructions for each part are displayed on the screen immediately before the start of the respective part.
In part 1, participants have to work on one of three different real effort tasks: slider task, encryption task or counting zeroes. The real effort tasks are similar in structure, but differ enough so that participants can form a true preference. For this reason, we also decided to implement three real effort tasks. The literature suggests that freedom of choice exists if there are at least two different options available. Nevertheless, to provide participants with a more meaningful choice, we provide three options.
First, we conduct a trial round, where participants have to solve one block of each of the three tasks. Then, they have to work on one of the tasks for 15 minutes. At this stage, our treatment variation comes into place. We vary whether subjects are assigned to a task (T1 and T2) or whether they can choose the task themselves (T3). In the pre-study, which is conducted first, we ask the participants if they want to choose the task themselves or if they want to sell their decision right to the experimenter for different amounts of money. We use an incentive-compatible choice list to elicit the WTA in the pre-study. There are several items, each with two choices: participants can either keep or sell the decision right. The amount of money obtained from the sale of the decision right increases with each item (the maximum is 5 Euros). After all decisions in the choice list are made, one item is randomly selected and the choice made in this item is implemented. If the decision right is sold to the experimenter, the participant receives the amount of money specified in the item and the participant is assigned to a task by the experimenter.
In T1, T3 and the pre-study, participants receive a flat payment of 10 Euros for stage 1 (“normal wage”). In T2, the participants receive 10 Euros and an additional unexpected wage increase, which is equal to the mean WTA to sell the decision right of participants in the pre-study. However, in all treatments, participants only receive the payment (normal wage or high wage, respectively) if they correctly solve a minimal number of items in the real effort task. If not, they do not receive a payment.
In the pre-study, we elicit the willingness-to-accept instead of the willingness-to-pay because we are interested in the value of the gift that we provide to the participants (instead of the value that the participants are willing to pay to receive the gift). Moreover, we ensure that participants in the pre-study have the choice between receiving a normal wage and a wage increase from selling their decision right (as in T2) or a normal wage and freedom of choice (as in T3).
After all participants have completed the task from part 1, we ask several non-incentivized questions about individual perceptions of the task. Additionally, we ask the participants who did not choose a task themselves which task they would have preferred to work on. In T3, we also ask participants for how much money they would have sold their decision right to the experimenter.
In part 2, participants are asked if they are willing to work on an additional task that is beneficial to the experimenter without receiving extra compensation. The task is to evaluate different real effort tasks. The real effort tasks and the evaluation criteria are taken from Charness et al. (2018). Since the participants worked on a real effort task themselves in part 1, it should be clear that the experimenters are interested in the general functionality and the outcomes of different real effort tasks. Furthermore, we explicitly tell the participants that working on the additional task is beneficial to the experimenters. This is no deception since we are interested in the perceived differences between the tasks: The results are relevant for the current research project presented here and for future projects of ours as well.
The additional task has 10 items. There is no time restriction. However, not all 10 real effort tasks have to be evaluated: the participants can stop working at any time. Once a participant decides to stop working, he goes straight to part 3. The same applies if a participant decides to not work on the additional task at all. We measure productivity in part 2 by counting how many real effort tasks have been fully evaluated.
In part 3, we conduct an incentivized cognitive ability task. The task is based on the IQ test by Frederick (2005) and consists of three questions. We use the results of the test to control for whether cognitive ability has an effect on effort.
In part 4, we conduct a charity dictator game. Participants receive 2 Euros and can make a donation to a charity of their choice (we provide them with a list of seven charities). We use the results of the dictator game to control for whether effort is provided due to reciprocity or altruism.