Experimental Design Details
Experimental design
Figure 1 illustrates the structure of Study 1. Participants were invited to take part in an experiment on “economic decision-making.” The study began with an introduction to lab-grown meat, followed by elicitation of participants' prior beliefs regarding its environmental and health impacts, as well as their willingness to pay (WTP) to learn findings from related impact research. Next, we disclosed the results of the incentivized elicitation approach and subsequently measured participants' stated WTP for lab-grown meat. Finally, we elicited their posterior beliefs to evaluate how the provided information influenced their perceptions.
Survey experiment sections
The survey, provided in the Appendix can be summarized as follows:
Introduction. We described lab-grown meat, highlighting the factors being considered to determine the environmental or health impact. To ease understanding of its impact, we provided current estimates of the health and environmental impact of meat.
Priors about impact. We elicited participants' prior beliefs. Specifically, we asked what they believed the impact on the environment and health is. Immediately after, we asked how sure they were about their answer to elicit confidence in priors (Dunning et al., 2019). We also asked a similar question about the expected impact of plant-based meat to determine whether participants have a greater knowledge on this topic compared to relative to lab-grown meat and whether lab-grown meat information has spillovers on beliefs of plant-based meat impacts before and after information is provided. WTP for information and belief updating. After the participants reported their priors, we offered the chance to purchase the findings from one of the four randomly chosen science-based report. The experimental currency in which we elicited WTP consisted of lottery tickets, which also incentivized participation. We initially endowed each participant with 10 such lottery tickets, each with a chance of winning one of 25 $30 e-gift cards. Participants could save their lottery tickets for the lucky draw or use some, or all of them, to learn about the environmental impact of lab-grown beef. Following a Becker-DeGroot-Marschak elicitation procedure (BDM), we measured the participant’s maximum WTP [0 to 10] to find out the results of the relevant study. We then drew a randomized price for the study. If the price was below the participant’s WTP, we revealed the findings and deducted the price from the participant’s stock of lottery tickets. To ensure that we observed belief updating for most participants, while maintaining incentive compatibility in the BDM procedure, the price was drawn from a distribution with high mass at zero ((Hjort et al., 2021). Consequently, we expect a high percentage of participants to receive the information regardless of their WTP. We emphasize this sample for the belief-updating analysis since these participants receive the information without selection. For those who received the information, we subsequently elicited posterior beliefs about the expected impact of lab-grown meat and plant-based meat that was not offered for purchase in this task. Before the WTP question, participants completed a standard attention check designed to assess how attentive participants were in the experiment.
Contingent valuation. At the very end, we elicited consumers’ willingness to pay (WTP) for two alternatives of burger patties: one made of lab-grown beef using a payment card. After the respondents selected an interval, they were asked to indicate the precise amount of money (Pavlova et al., 2004). This combined elicitation method offered two important advantages. First, it facilitated the respondents’ answers by providing a price tag (Baji et al., 2014), while addressing value cues and the starting point biases associated with other methods (closed-ended questions and the bidding games). Second, it allows the stated WTP to be measured on a continuous scale (Whynes et al., 2003).
Respondents were asked to choose a payment scale from a list of price intervals that could best reflect the maximum price he/she is willing to pay for 1.33 pounds—equivalent to 4 1/3-pound patties—of the meat alternatives under consideration. Then they were asked to point out how much they would pay. Respondents were informed about the average price of 1.33 pounds of conventional ground beef—about eight dollars—in the US market in August 2024. The payment card itself includes 13 price intervals, ranging from 0 to 60, with the length of each interval being five dollars (B. Chen et al., 2023). If the respondent’s WTP is above 60 dollars, he/she can choose the price interval of 60 dollars or above. To minimize the hypothetical bias of this contingent valuation question, we employed a cheap talk script (Cummings & Taylor, 1999), respondents were instructed to state their WTP as if they were presented with actual products in a real shopping situation.
Exit Questions: Participants were asked to rate the reliability of the information provided on a standard 5-point scale (1 = unreliable, 5 = reliable) (Roozenbeek & Van Der Linden, 2019). Perceived naturalness for acceptance of lab-grown meat was elicited (Siegrist & Sütterlin, 2017; Wilks & Phillips, 2017) as well as questions on political affiliation and taste perception were also included. (Wilks & Phillips, 2017).