Abstract
Health and safety officials are sometimes placed in an awkward position: knowing that a foodborne disease outbreak is occurring but not knowing which food is responsible. They have to advise consumers, but relying on ambiguous and evolving information raises the question, how do consumers respond to changing advice? Here, we estimate a model of the retail demand for tomatoes in the USA, accounting for the 2008 events in the USA in which consumers were advised that some types of tomatoes were contaminated with Salmonella bacteria, and later were advised that tomatoes were safe and peppers were not. Using the quantity of news media attention given to the Salmonella issue, we show that consumers generally responded to the advice that tomatoes were contaminated, but did not respond to the declaration that tomatoes were safe. The magnitude of response to contemporaneous news depended on the extent of coverage in previous weeks.
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Notes
Even if tomatoes had been confirmed as a vehicle, FDA would eventually have told consumers that all tomatoes on the market were safe to eat. Tomatoes come from different regions during the year and at some stage all tomatoes from regions that were in production when the outbreak first started would have been off the market as tomatoes from other regions begin to fill the supply chain.
CDC coordinates a national network of public health and food regulatory agency laboratories called PulseNet. Participating laboratories perform standardized molecular subtyping of foodborne disease-causing bacteria. These DNA patterns are submitted electronically to a dynamic database at the CDC, allowing for rapid comparison of the patterns.
An incorrect attribution occurred in 1996 when the Texas Department of Health incorrectly identified California strawberries as the source of a foodborne illness outbreak in the United States and Canada due to Cyclospora; 19 days later the New York Public Health Department announced that the outbreak was linked to raspberries (Calvin et al. 2002; Richards and Patterson 1999). However, it has been much more common that government officials cannot identify the contaminated product. In 2008, only 64% of foodborne illness outbreaks could be traced to a single confirmed or suspected food product (Gould et al. 2011).
The Produce Safety Project at Georgetown University (2008) included a detailed timeline of events related to the outbreak, focusing on public sector activities. One television news report noted FDA’s interest in cilantro, but the timeline identified July 7 as the day CDC announced it was also examining cilantro as a potential source of contamination. As there was not a second reference to cilantro in the timeline and there was no further television coverage of cilantro as a source of contamination, we dismissed interest in cilantro as influencing the demand for tomatoes. Tomatoes were declared safe mid-week during week 6 of the news so we opted to model the impact of the safety declaration beginning week 7.
The PEW Research Center has conducted national surveys of Americans annually since 2001 on the sources they use for news (PEW Research Center for the People & the Press 2011). Trends show that television and newspapers have declined as the internet has rapidly increased. Even so, their survey conducted December 1–5, 2010 among 1,500 adults shows the importance of television as a news source. “Television remains the most widely used source for national and international news—66% of Americans say it is their main source of news—but that is down from 74% three years ago and 82% as recently as 2002” (PEW Research Center for the People & the Press 2011).
The length of news coverage also limited lag structure. The tomato warning (safety declaration) news lasted 6 (two) weeks, so interactions further than 6 (two) weeks apart on the R 1(R 2) variable will be zero.
Using a Box–Cox power transformation of the news variables, we found that the linear model performed just as well as all the models with different power transformations.
The adding-up restriction \( \mathop{\sum}\limits_{i=1}^4{\alpha_i}=1 \) was modified to account for the lagged dependent variable so that the restriction became \( \mathop{\sum}\limits_{i=1}^4{\alpha_i}+\mathop{\sum}\limits_{i=1}^4{{\overline{S}}_i}{\rho_i}=1, \) where \( \mathop{\sum}\limits_{i=1}^4{{\overline{S}}_i}{\rho_i}=0.5. \) \( {{\overline{S}}_i} \) are mean shares and ρ i are estimated coefficients on lagged dependent variables. The latter condition avoids conditions that might force a lagged variable coefficient to be negative.
No news interaction terms were statistically significant in the upper-stage model and thus did not influence overall expenditures.
References
Barton Behravesh, C., Mody, R. K., Jungk, J., Gaul, L., Redd, J. T., Chen, S., et al. (2011). 2008 Outbreak of Salmonella Saint Paul infections associated with raw produce. The New England Journal of Medicine, 364, 918–927.
Blaylock, J. R. (1989). An economic model of grocery shopping frequency. Applied Economics, 21, 843–852.
Calvin, L., Foster, W., Solorzano, L., Mooney, J. D., Flores, L., & Barrios, V. (2002). Response to a food safety problem in produce: A case study of a Cyclosporiasis outbreak. In B. Krissoff, M. Bohman, & J. Caswell (Eds.), Global food trade and consumer demand for quality (pp. 101–127). New York: Kluwer Academic Publishers.
Carpentier, A., & Guyomard, H. (2001). Unconditional elasticities in two-stage demand systems: An approximate solution. American Journal of Agricultural Economics, 83, 222–229.
Centers for Disease Control and Prevention. (2008). Outbreak of Salmonella serotype Saintpaul infections associated with multiple raw produce items—United States, 2008. Morbidity and Mortality Weekly Report, 57, 929–934.
Centers for Disease Control and Prevention. (2010). Salmonella outbreak investigations: Timeline for reporting cases. Updated August 9, 2010. Accessed July 8, 2011. http://www.cdc.gov/salmonella/reportingtimeline.html.
Centers for Disease Control and Prevention. (2012). PulseNet & foodborne disease outbreak detection. Updated February 24, 2012. Accessed March 19, 2012. http://www.cdc.gov/features/dsPulseNetFoodborneIllness/.
Cowell, A. (2011). Case tying E. coli to sprouts strengthens in Germany. New York Times June 11: A5.
Dahlgran, R. A., & Fairchild, D. G. (2002). The demand impacts of chicken contamination publicity—A case study. Agribusiness, 18, 459–474.
Deaton, A., & Muellbauer, J. (1980). An almost ideal demand system. The American Economic Review, 70, 312–326.
European Food Safety Authority. (2011). Tracing seeds, in particular fenugreek (Trigonella foenum-graecum) seeds, in relation to the Shiga toxin-producing E. coli (STEC) 0104:H4 2011 outbreaks in Germany and France. Updated July 5, 2011. Accessed July 10, 2011. http://www.efsa.europa.eu/en/supporting/pub/176e.htm.
Gould, L. H., Nisler, A., Herman, K., Cole, D., Williams, I., Mahon, B., et al. (2011). Surveillance for foodborne disease outbreaks—United States, 2008. Morbidity and Mortality Weekly Report, 60, 1197–1202.
Green, R., & Alston, J. M. (1990). Elasticities in AIDS models. American Journal of Agricultural Economics, 72, 442–445.
Lloyd, T. A., McCorriston, S., Morgan, C. W., & Rayner, A. J. (2006). Food scares, market power and price transmission: The UK BSE crisis. European Review of Agricultural Economics, 33, 119–147.
Lusk, J. L. (2010). The effect of Proposition 2 on the demand for eggs in California. Journal of Agricultural & Food Industrial Organization, 8, article 3.
The PEW Research Center for the People & the Press (2011). More young people cite internet than TV: Internet gains on television as public’s main news source. Jan. 4, 9 pp. Accessed July 31, 2012. http://www.people-press.org/files/legacy-pdf/689.pdf.
Piggott, Nicholas, E., & Marsh, T. L. (2004). Does food safety information impact U.S. meat demand? American Journal of Agricultural Economics, 86(1, Feb), 154–174.
Produce Safety Project at Georgetown University. (2008). Breakdown: Lessons to be learned from the 2008 Salmonella Saintpaul outbreak. Nov. 17, 32 pp. http://www.pewhealth.org/reports-analysis/reports/lessorns-to-be-learned-from-the-2008-salmonella-saintpaul-outbreak-85899368519 Accessed July 10, 2011.
Richards, T. J., & Patterson, P. M. (1999). The economic value of public relations expenditures: Food safety and the strawberry case. Journal of Agricultural and Resource Economics, 24, 440–462.
Swartz, D. G., & Strand, I. E., Jr. (1981). Avoidance costs associated with imperfect information: The case of Kepone. Land Economics, 57, 139–150.
Smith, M. E., van Ravenswaay, E. O., & Thompson, S. R. (1988). Sales loss determination in food contamination incidents: An application to milk bans in Hawaii. American Journal of Agricultural Economics, 70, 513–520.
World Health Organization. (2011). Outbreaks of E. coli O104:H4 infection: Update 30 Updated July 22. Accessed December 19, 2011. http://www.euro.who.int/en/what-do-we-do/health-topics/emergencies/international-health-regulations/news/2011/07/outbreaks-of-e.-coli-o104h4-infection-update-30.
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The authors thank the editor and three anonymous reviewers for their suggestions and comments, but retain responsibility for any remaining errors. The views expressed here are those of the authors and cannot be attributed to the Economic Research Service or the U.S. Department of Agriculture.
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Arnade, C., Kuchler, F. & Calvin, L. Consumers’ Response When Regulators Are Uncertain About the Source of Foodborne Illness. J Consum Policy 36, 17–36 (2013). https://doi.org/10.1007/s10603-012-9217-6
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DOI: https://doi.org/10.1007/s10603-012-9217-6