Experimental Design
The study consists of three parts that run over a succession of 12 days: (i) the initial instructions (Day 1), (ii) the main decision task (Day 2 - Day 11) and (iii) the final questionnaire (Day 12). After Day 12 subjects will receive a payment reflecting their choices in (ii) and a bonus payment if they fill out the final questionnaire (iii).
The decision task consists of a succession of up to ten decisions made on subsequent days. On the first day of the decision task subjects are endowed with an initial lottery. This lottery has two outcomes (yellow or green) each of which is associated with a specific payoff. Each decision affects the payoff associated with each outcome. To make a decision subjects can log into an online program via their computer or smartphone. At the instructions day (i) subjects choose a window of 4 hours in which they can log into their software and a user code prevents multiple participation.
After logging into the software, subjects see the current lottery and its payoffs. Depending on the treatment condition an adjustment to these payoffs can be made by (a) clicking a button (active condition) or (b) taking no action (passive condition). If no action is taken (or subjects do not log into the software) in the active condition the current lottery is selected at the end of the decision window. In the passive condition, subjects can halt further adjustment steps by clicking on a button during an active decision window. If subjects do not log into the software or do not press the button to halt further adjustment steps another adjustment step is taken.
To disentangle the mode of choice from a status-quo effect, we furthermore varied whether subjects start from an initially safe lottery, such that any adjustment of the lottery implies more risk-taking, or from an initially risky lottery, such that adjustments lead to less risk-taking.
The size of an adjustment step is unknown to subjects. They are made aware that payoff is getting less (more) similar in the safe (risky) condition and that the lottery on the last day will be maximally risky (safe) in the safe (risky) condition. They are also told the highest and lowest possible adjustment step in each condition. This ensures that subjects do have an incentive to log into the software to find out the payoffs of the current lottery.
In the safe treatment, both lottery payoffs (green and yellow) of the initial lottery payoffs are set to 6. In the risky treatment, one payoff is 0 the other is at 15. Adjustment step sizes are structured in a way that ensures that the safe (risky) starting point lotteries always reach 0/15 (6/6) Euro after 10 adjustment steps. That is, there is a predetermined
set of possible step sizes. These range from 0.5 to 0.75 €. The order of implementation of these step sizes is randomly determined for each participant.
The questionnaires serve two purposes. On the one hand, in the initial questionnaire, we elicit some basic demographic information (gender, age, math grade, subject of studies, available income, smoking behavior, dental checkups). On the other hand, we use the final questionnaire as a measure for sample attrition. Subjects who do partake in the final questionnaire can be assumed to have not selected out of the experiment at an earlier stage. In the final questionnaire, we elicit additional demographic information and information regarding decisions in the study (SOEP Measure of risk aversion, aim to earn as much as possible in the study, the difficulty of remembering to take a decision, remember/forget to log in, number of participations in previous studies, issues with understanding the instructions, purpose of study)