Thai consumer willingness to pay for differing GM labeling policies : comparisons across time

Thailand has adopted a labeling policy on genetically modified (GM) food items since 2003 that if their ingredients are derived from soybean and corn, a mandatory label is required when their GM content reaches a 5% threshold level. However, critics disagree and demand a mandatory lower threshold requirement. The purpose of this research paper is to compare Thai consumers in 2009 and 2021 regarding their willingness to pay for GM food and quantify the premium for non-GM food. The demand-revealing mechanism used in this research is the experimental auction, specifically the random nth-price auction. One hundred and twenty-one participants took part in the experiment in both periods, in which they had to bid for food products affixed with newly constructed labels. Results show that Thai consumers do not strongly oppose GMOs, and the opposition appears to be weakening over time, as the average discount of GM food was 6.74% in 2009 and 3.08% in 2021. Thai consumers in 2009 did not view 1%, 5%, and higher percentages of GMO content differently. On the other hand, since they did not perceive a GM level of 5% as being GM-free food, the adoption of a 5% threshold level is supported until further research has been carried out on the cost implications. Consumers in 2021 appeared to be insensitive to the 5% threshold level and significantly assign the average premium of 10.94% to GM-free food. Nevertheless, market opportunities exist for GM food sellers if they clearly post GMO benefits on their labels.