sealPurdue News

April 16, 2002

Europeans can't tell modified food by their labels, study finds

WEST LAFAYETTE, Ind. – Although studies have found that 80 percent to 90 percent of Europeans say they don't want genetically modified foods, manufacturers who sell both genetically modified and conventional products have noticed that the two versions sell about the same.

It's a paradox, and one that is important to food producers, farmers and other agribusinesses.

But it was not a surprise to Charles Noussair, associate professor of economics at Purdue University's Krannert School of Management, who says it is common for public opinion and consumer behavior to differ.

"Opinion surveys capture the respondent in the role of a voter, not in the role of a consumer," he says. "The two behaviors can be quite different, as many studies have shown."

Noussair and colleagues in Europe conducted experiments to investigate the paradox. Their research found that despite the high level of opposition to genetically modified foods, most Europeans aren't concerned enough to read ingredient lists on food packaging.

The results were published in the most recent issue of the academic journal Economic Letters.

The study found that consumers didn't notice a food contained genetically modified products even after they were seated and left for three minutes with nothing to but to look at the ingredient label. The research paper dryly noted, "What is not read in the laboratory will probably not be read in the supermarket."

In the study, consumers were given 150 francs ($21 U.S.) and asked to bid on a product. The consumers bid on large chocolate bars made by a major multinational company that produces both genetically modified and non-genetically modified foods.

Consumers could bid on what they thought the product was worth in a process akin to a game on "The Price is Right." In this case, however, the game is actually a sophisticated survey technique called the Vickery Auction, named after William Vickery, who won the 1996 Nobel Prize in economics.

The study found that even after they were told the chocolate bars contained genetically modified ingredients, most of the consumers participating in the research were willing to buy the genetically modified foods, but only if the price was about one-third less than conventional products.

The study and subsequent report was funded by a partnership of 37 organizations, corporations and governmental agencies composed of groups as divergent as Monsanto and Greenpeace. The researchers worked under the aegis of the French agricultural ministry.

As a result of the study, the researchers are advising European nations to put a large label on the foods indicating they contain genetically modified ingredients in addition to putting the information in the list of ingredients.

Bernard Ruffieux, professor at the Institut National Polytechnique de Grenoble and Grenoble University, in Grenoble, France, says labeling of genetically modified foods is a major public issue in Europe.

"It's a big issue for us because we're importing a lot of maize and soya [corn and soybeans], and these are used in many of our foods," he says. "It's also a big issue because now the food markets are globalized. The demand of the consumers for information is spreading around the world."

Although foods that contain genetically modified ingredients are not cheaper now, that situation may change as new advances in biotechnology are put into production.

Noussair says the research shows that labeling would allow a separate market for genetically modified foods in Europe.

"We believe there would be a market for genetically modified foods in Europe if they had a distinct advantage, such as reduced cost," Noussair says. "This situation might very well be different in the United States, where such distinct and separate markets may not exist."

Despite the recommendation, Noussair says that some economists are opposed to unnecessary labels and segregated markets.

"It's very costly to keep genetically modified and non-genetically modified crops and foods separate in the production stream," he says. "To an economist it creates a deadweight expense if there is no reason for doing it. However, given our data, we think that there is good reason to have separate production tracks in Europe."

In the United States the law requires genetically modified products to be labeled only if there is an actual change in the food that affects humans.

"Non-labeling is a science-based policy, and that is what we have in the United States," Noussair says. "Most scientists are opposed to labeling unless there are specific known health and environmental consequences of using the product."

The study was conducted in 16 sessions in Grenoble, France. That city was chosen because surveys have shown their views toward genetically modified foods are very similar to those of the Europeans overall.

"French responses are very, very close to the European average," Noussair says. "They are more vocal about their views on the issue, but their views are approximately the same."

The study also used a cross-section of the population, which Noussair says is unusual for such research.

"Ninety-nine percent of such studies are conducted with college students, and they are actually much easier to do," he says. "There are methodological changes you have to make when you survey real people."

Ruffieux says one amusing aside was that even though the people participating in the survey were offered portions from the same large chocolate bar, some participants said they thought the second portions weren't as tasty as the first portion even though the servings were identical.

"It's amazing that once you think the product contains something you think you don't like that you think it tastes differently," he says.

Writer: Steve Tally, (765) 494-9809,

Sources: Charles Noussair, (765) 494-4416,

Bernard Ruffieux, +33 (0)4 76 57 45 64,

Ag Communications: (765) 494-2722; Beth Forbes,;

NOTE TO JOURNALISTS: A copy of the paper mentioned in this article is available to working journalists from Steve Tally, (765) 494-8396,


Do consumers not care about biotech foods
or do they just not read the labels?

Charles Noussair, Purdue University, West Lafayette, Ind.; Stephane Robin, and Bernard Ruffieux, Ecole ationale Superieure de Genie industriel, Grenoble France

We conduct an experiment to study the discrepancy between European public opinion and consumer purchase behavior with regard to genetically modified organisms in the food supply. We find that consumers are typically unaware of the labeling indicating genetically modified content.

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