Experimental Design Details
The start survey includes questions about gender, dietary habits, and investment experience to gather initial background information. These variables are used as controls in the study. Subjects may choose “Prefer not to answer” for these questions.
The instructions will outline the real effort and investment task crucial to the experiment. Subjects are informed of these tasks and must answer three comprehension questions to confirm their understanding. If a subject is unable to answer all questions correctly on the third attempt, the experiment is terminated.
The message treatment consists of two levels (optimistic, skeptical) implemented in a between-subjects design, where subjects are randomly assigned to one of the treatment groups or to the control group to ensure comparability.
Treated subjects receive either an optimistic or skeptical text about green investing, which sets the tone for subsequent decision-making processes. These message treatments are designed to induce social norms that influence subjects' beliefs and behaviors toward green investing.
Following the message exposure, subjects will be asked to indicate their willingness to pay for a green asset such that they are indifferent between that asset and a conventional asset. This is followed by a series of five questions designed to assess subjects' beliefs about green investing on a Likert scale from 0 (strongly disagree) to 10 (strongly agree).
In the real effort task, subjects perform a numbers-to-letters decoding task to increase the probability of seeing information about carbon offsets in the investment task. Each correct answer adds 40% of the remaining distance to 100% to the probability, ensuring a steady growth that gradually decreases. The probability reaches 100% after eleven correct answers. Subjects can move on to the investment task at any time.
Subjects then complete an investment decision task in which they can allocate their endowment among four risky assets and one risk-free asset. They specify the allocation to the four risky assets, and the amount invested in the risk-free and interest-free asset is automatically calculated. One of the risky assets is a true green asset that generates more carbon offsets than the management fee (15% vs. 1.5%), while another green asset is considered greenwashed (0.75% vs. 1.5%). In addition, two conventional assets are available: one with independent returns, offering diversification potential, and another with returns that are drawn simultaneously with the returns of the green assets, making them identical.
Subjects progress through the decision-making process over five rounds, one of which is randomly selected for their bonus payment, emphasizing the incentivized nature of the experiment. Upon completion of all five rounds, subjects receive feedback on the results of the random processes and are provided with details of their bonus payment.
Following the experimental tasks, manipulation checks are conducted to assess subjects' perceptions of the treatments (optimistic, skeptical). In the exit survey, key measures, including a subset of the Environmental Portrait Value Questionnaire and an assessment of their financial literacy, are administered to capture intrinsic values and financial understanding, providing a more comprehensive insight into subjects' decision-making processes.