Food safety prevention efforts may fail, and then health and safety officials try to protect consumers by tracing the source of a foodborne illness outbreak. When successful, health and safety officials can identify the contaminated food and then warn consumers to avoid it. This warning may result in fewer foodborne illnesses. If consumers are vigilant and follow advice from health and safety officials, retail demand would fall to zero on advice to avoid a food, and would remain zero until news that the food was no longer a source of contamination. At that point, demand would likely return to its pre-warning state. Demand, and in turn health impacts, become more difficult to gauge, however, if consumers are not vigilant about keeping abreast of food safety warnings, do not take warnings by health and safety officials seriously, or forget the advice. Thus, an "all clear" signal by officials might or might not return demand to normal. The speed at which consumer demand returns to normal will affect revenues received by food suppliers.

Some consumers avoid purchasing foods they perceive as unsafe, including some imported foods, and they may choose food products they believe to be safer, such as irradiated meat or organic food. Even after a safety problem with a particular food has been resolved, consumer perceptions about the implicated food product and about the ability of the supplier or exporting country to produce safe food may be slow to change. Such perceptions may have a lasting influence on food demand and global trade.

Consumers Respond to News from Health and Safety Officials

On September 14, 2006, FDA announced that consumers should not eat bagged spinach. Epidemiological evidence pointed to bagged spinach (fresh ready-to-eat spinach that arrives at retail stores already in bags) as a possible cause of an ongoing multistate foodborne illness outbreak of the potentially deadly bacterium E. coli O157:H7. The next day, FDA expanded the warning to include all fresh spinach—both bulk and bagged.

ERS research revealed that consumers responded specifically to the FDA announcement—spinach sales plunged, but consumers did not panic and avoid other vegetables. The short-term impact was a drop in demand for all leafy greens, as consumers briefly substituted other vegetables for leafy greens. Over the long term, consumers shifted purchases among leafy greens, but total expenditures for leafy greens did not change. The analysis showed that consumers slightly reduced total leafy greens expenditures in favor of other vegetables but returned to their previous total leafy greens expenditure levels by 16 weeks after the outbreak was announced. The major change was a shift in expenditures among the six categories of leafy greens.

The ERS analysis suggests that many consumers can and do use all the information they are given about product contamination to make fine distinctions among food products. The analysis of retail sales suggests that consumers rapidly responded to FDA's information. (See "Consumers' Response to the 2006 Foodborne Illness Outbreak Linked to Spinach.")

Health and safety officials are sometimes called upon to tell consumers that a food is safe, despite media attention to the contrary. In 1996, the United Kingdom announced that BSE was linked to a new human disease, new variant Creutzfeldt Jakob Disease (nvCJD). This rare, but invariably fatal, human strain causes progressive deterioration of brain tissue and had caused 164 human deaths in the UK as of February 2, 2009. After the 1996 announcement, domestic sales and consumption of beef products in the UK fell by 40 percent. Trade was also heavily affected as the European Union banned imports of live cattle and bovine products from the U.K. In the U.S., however, reaction to domestic BSE was muted. U.S. government announcements in 2003 that one cow imported from Canada was infected with bovine spongiform encephalopathy (BSE) affected the sales of some beef products for no more than two weeks.

The announcements were not warnings. Officials from USDA and other agencies made unequivocal statements that the U.S. food supply was safe, in effect telling consumers not to be concerned with the BSE findings: the likelihood of exposure to BSE was near zero and likely to fall. The statements also gave agencies an opportunity to highlight programs and activities targeted at managing the risk of BSE. Like the experience with spinach, consumers appeared to pay attention to the message from health and safety officials, largely responding as they recommended. See:

Did BSE Announcements Reduce Beef Purchases?

Evidence from some other countries suggests qualitatively similar responses to information about potential health hazards. ERS researchers used Italy as a case study to examine consumers' responses to newspaper articles on avian influenza (bird flu) from October 2004, after reports of the first outbreaks in Southeast Asia, through October 2006, beyond the point at which outbreaks were reported in Western Europe. Larger numbers of newspaper reports on bird flu led to larger reductions in poultry purchases. Most impacts were of limited duration, and all began to diminish within 5 weeks. See:

The Effects of Avian Influenza News on Consumer Purchasing Behavior: A Case Study of Italian Consumers' Retail Purchases

U.S. demand for Guatemalan raspberries fell after a 1996 outbreak caused by the foodborne parasite, Cyclospora, which resulted in 1,465 illnesses in the United States and Canada. By July 1996, the U.S. CDC declared Guatemalan raspberries the likely source of the illnesses. After additional outbreaks in 1997, the U.S. FDA issued an import alert for Guatemalan raspberries for the spring 1998 season. Although the Cyclospora problem with Guatemalan raspberries has been resolved, changes in consumer demand and trade continue to persist. Demand for Guatemalan raspberries has been restored to only about one-third of its pre-outbreak levels.

See "Effects of Food Safety Perceptions on Food Demand and Global Trade" in the following report:

Changing Structure of Global Food Consumption and Trade

Purchasing Foods Marketed as Safer

Consumers may have the opportunity to purchase foods processed with extra steps, such as irradiation, to further reduce the risk of harmful bacteria. ERS researchers found that in a  survey by the Foodborne Diseases Active Surveillance Network (FoodNet), half of the respondents were willing to buy irradiated ground beef or chicken, and a fourth were willing to pay a premium for these products, which cost more to produce than comparable nonirradiated products. These findings suggest that the impact of food irradiation on public health will be limited unless consumer preferences change, perhaps in response to educational messages about the safety and benefits of food irradiation. See: 

Consumer Acceptance of Irradiated Meat and Poultry Products

ERS research shows that some consumers perceive organic products as a safe and healthy way to avoid potential risks of exposure to pesticide residues in foods. Sales of organic baby food have been steadily increasing, and in 1995 totaled more than $25 million. This was despite a price premium of 21 cents per jar over regular baby food. (See "Consumers Pay a Premium for Organic Baby Foods").