Willingness to Pay for Genetically Modified Oil, Cornflakes, and Salmon: Evidence from a U.S. Telephone Survey

Abstract

This paper reports results from a U.S. national telephone survey on genetically modified foods (vegetable oil, cornflakes, and salmon). The survey featured a contingent valuation in which respondents chose between the GM and non-GM alternatives with an option of indifference. The binomial and multinomial logit models yielded estimated willingness to pay (WTP) to avoid the GM alternatives. Respondents were willing to pay 20.9%, 14.8%, 28.4%, and 29.7% of the base prices to avoid GM vegetable oil, GM cornflakes, GM-fed salmon, and GM salmon, respectively. The inclusion of indifference option could increase the sample size and moderate the mean WTP.

Using Stated Preference and Prior Purchase Intention in the Estimation of Willingness to Pay a Premium for Genetically Modified Foods

“…However, because the initial bid, B I , was a fixed value equal to the average market price of non-GM-fed beef rather than a randomly assigned bid value conventionally used in a standard double-bounded design, the nonrandomness of B I might have made the fitting of a double-bounded CV model inappropriate. Kaneko and Chern (2005) designed a questionnaire similar to Li et al's (2004) with more options for a consumer to select his or her preferred goods. They first requested respondents to choose, at the market price of the non-GM food at the survey time, a preference from (1) non-GM, (2) GM alternative, (3) Indifferent, or (4) Neither.…”

“…Inclusion of the indifference option in the CV question by Kaneko and Chern (2005) was an interesting idea. The indifference option provides a consumer with an alternate choice so that he or she is not forced to give a dichotomous response when he or she truly has no preference between the two products.…”

“…The possibility of estimation bias due to protesters, however, did not receive much attention in the studies of Li et al (2004) and Kaneko and Chern (2005). Kaneko and Chern asserted that the study of WTP should focus on the "optimizers," i.e., those consumers who would change their choice when they faced a substantial price markdown.…”

“…Their argument was conceptually correct, but they failed to provide a convincing screening procedure to separate protesters from "optimizers." In their study, Kaneko and Chern (2005) attempted to utilize the Neither option in their initial CV question in the hope of separating protesters from optimizers. However, we believe that their procedure is only of limited help in filtering out those protesters.…”

Consumer Purchase Intention towards GeneticallyModified Food: Beneficial, Price, Socio-Demographicand Label Determinants

“…For example, if a GM food contained genetically modified animal ingredients, consumer's awareness to it would increase. [4] In china, there is a big difference among the different findings. A computer-assisted telephone survey to Guangzhou, Shanghai and Beijing organized by Greenpeace showed that only 35% of respondents will or are likely to purchase the GM food.…”