Experimental auctions, collective induction and choice shift: willingness-to-pay for rice quality in Senegal

Abstract

We propose a collective induction treatment as an aggregator of information and preferences, which enables testing whether consumer preferences for food quality elicited through experimental auctions are robust to aggregation. We develop a two-stage estimation method based on social judgment scheme theory to identify the determinants of social influence in collective induction. Our method is tested in a market experiment aiming to assess consumers' willingness-to-pay for rice quality in Senegal. No significant choice shift was observed after collective induction which suggests that consumer preferences for rice quality are robust to aggregation. Almost three quarters of social influence captured by the model and the variables was explained by social status, market expertise and information.

Consumer preferences for micronutrient strategies in China. A comparison between folic acid supplementation and folate biofortification

“…Second, indifference is more likely to occur in the morning sessions, while participation in the afternoon increases the likelihood to choose FBR. While several auction studies with staple crops reported higher WTP values in the morning (42,43,73,74) , which is likely due to hunger and increased interest in buying and consuming food, the present study reports a somewhat similar time-ofthe-day effect that refers to product choice. Respondents in the morning are more favourable to all folate products, rather than preferring one.…”

“…Hence, we address the need to include substitutes in GM food auctions (35)(36)(37) . Such a multiple-product auction design is often applied to simultaneously determine consumers' WTP for different food products (38)(39)(40)(41) , including rice (42,43) , GM foods (44)(45)(46) and biofortified crops (47) . While FAR is currently not sold at the marketplace, FBR is still in a development phase.…”

“…Besides GM foods with farmer benefits (55) , such as insect-resistant rice in China (28) , experimental auctions are more and more applied to analyse WTP for GM crops with consumer/health benefits (45,56,57) , and GM biofortified crops (Golden Rice) in particular (36,52) . Besides provitamin A, rice auctions have also examined other quality attributes like quality labels in Senegal (42) and parboiling technologies in Benin (43) . The auctions are targeted towards female rice consumers of childbearing age from Shanxi Province, i.e.…”

Radio Messaging Frequency, Information Framing, and Consumer Willingness to Pay for Biofortified Iron Beans: Evidence from Revealed Preference Elicitation in Rural Rwanda

“…The results suggest that the premium estimations are not driven by these factors. Although we have shown that the social interaction effect can be eliminated when the difference in WTP is modeled, a more robust approach of collective induction based on social judgment theory can be built into the design of future experimental auctions to rigorously identify the social interaction effect (Demont et al 2013). An examination of the effects of hypothetical bias or participants' inability to make an out-of-pocket payment after "winning" in the experiment is a significant part of this analysis.…”

Randomization to treatment failure in experimental auctions: The value of data from training rounds

“…Half of the sessions were conducted at 12 pm and half of the sessions were conducted at 1 pm. We only allowed a one hour difference between scheduled sessions to minimize potential "time of the day" effects on bidding behavior (Demont et al, 2012(Demont et al, , 2013Hoffman et al, 1993;Menkhaus et al, 1992;Morawetz et al, 2011). Since we could not fully control subjects' eating behavior before participating in the auction, we also asked subjects to self-report their hunger level.…”