1. Oyster Demand Adjustments to Alternative Consumer Education and Post Harvest Processes in Response to Vibrio vulnificus – A Pilot Study
Ash Morgan, William Huth, Greg Martin
University of West Florida
CNREP, New Orleans, May 2007

2. Vibrio v. Vibrio v. is a bacterium
Found naturally in estuarine or brackish coastal waters
Higher concentrations in summer months
Filter-feeding shellfish concentrate Vibrio v. in tissues

3. Gulf of Mexico Oyster Industry
Vital resource
Gulf of Mexico oyster industry
Average annual landings of eastern oyster = $47 million (82%)
Gulf also supports recurring Vibrio v. incidences

4. Human Health Risk?
Risk of life-threatening illnesses (acute septicemia or blood poisoning) to individuals with certain health conditions
Liver disease
Diabetes
Cancer
Weakened immune system

5. Actual Risks 1989 – 2002 Cocoran (1998)
FDA recorded 341 Vibrio v.-related serious illnesses
98% associated with consuming raw oysters
179 resulted in deaths
Cocoran (1998)
50 people become ill and 10 die each year through eating raw Gulf Coast oysters contaminated with Vibrio v.

6. Industry Cause for Concern?
Recurring incidences
Raise consumer awareness of product safety
Increase perceived risk associated with oyster consumption
ISSC survey
One-third of respondents reduced oyster consumption in 2003
Primary reason
Personal heath concerns
Lipton (1997)
$43 million loss due to increased awareness among consumers

7. Research Objectives
Measure changes in oyster demand as a function of perceived risk
Negative and positive information treatments
1) Quantify welfare losses due to news of Vibrio v. on demand for oysters
2) Quantify effects of different educational treatments (medium*source) in mitigating welfare losses
3) Quantify differences in risk perceptions contingent on PHP alternatives and price points

8. Research Strengths Strong policy application Priority topics:
Industry and institutional interest
Fit with ISSC/IFAS research
Priority topics:
ISSC
Consumer education strategies to better inform oyster consumers of actual risks associated with Vibrio v.
IFAS
socioeconomic impacts from regulatory issues in the shellfish industry
focus on the economic consequences of PHP requirements

9. Research Strengths FDA mandates
Development and implementation of educational and outreach programs
Inform consumers about risks associated with Vibrio v.
Florida Vibrio v. Risk Reduction Plan for Oysters
“Consumer education first and foremost tool to reduce illness related to Vibrio v.”

10. Background Shulstad and Stoevener (1978) - Pheasants
Swartz and Strand (1981) – Baltimore oysters
Smith et al. (1988) – Milk
Brown and Schrader (1990) – Eggs
Wessells et al. (1995) – Mussels
Parsons et al. (2006) - Pfiesteria

11. Background
Significant welfare losses due to Pfiesteria-related fish kills
Positive information little impact on consumer behavior
Individuals are not responsive to “expert” risk information
Could be due to source credibility issues

12. Survey Design Follow Parsons et al. (2006) framework
2-stage web-based contingent behavior analysis
Provide respondents with information treatments
Respondents asked series of CB questions
Elicit oyster demand preferences under different information scenarios

13. Stage One Traditional telephone survey Pre-treatment baseline data
Oyster consumption experience, attitudes, preferences
Awareness/perceptions of health risks
Demographic data
Respondents asked to participate in Stage 2

14. Stage Two Respondents sent link to project web site
Unobtrusive identifier code
Respondents subject to different media treatments*source
Change in oyster meals consumed

16. Treatments Fictitious newspaper article Based on actual report
Death caused by consuming contaminated raw oysters

17. Treatments*Source Information treatments Sources
Tri-fold color brochure
30 second video PSA format
Newspaper / magazine format
Sources
ISSC/Food and Drug Administration (FDA)
A fictitious “brand identity” that identifies Vibrio v. education programs (“American Shellfish Foundation”)
Control group (no message source identified)

18. Example – Brochure/ISSC-FDA
Respondents informed brochure is published and distributed by the U.S. Food and Drug Administration (FDA) and the Interstate Shellfish Sanitation Conference (ISSC).
Brief description of ISSC and FDA mission and funding source.

21. Generic PHP Treatment Focus of oyster industry on PHP treatments
4 FDA-approved PHP systems
Pressurized
Pasteurized
Freezing
Irradiation

22. PHP
Respondents exposed to textual material containing non-technical educational information about the concept and efficacy of various types of PHP treatments to mitigate the risk of Vibrio v. infection.
2 final CB questions
Consumption of PHP-treated oyster
Consumption of PHP-treated oyster + price increase

23. Model

24. Estimation 14 parameters to be estimated: price increase
price decrease
news
9 media*source treatments
PHP
PHP + price increase
Estimate Demand Curve
Demand Shifters

25. Results
Quantify the effectiveness of all media x source treatments, including PHP and price premium, in mitigating any negative welfare effects from the perceived risk effects of Vibrio v.
Provide interested parties such as the ISSC with data to support further development of interventions that improve consumer education strategies and risk mitigation.

26. Descriptive Stats n=366 58.8% are oyster consumers
Mean meals per month = 2.2
77% eat 1 to 2 meals per month
33.2% eat raw oysters
45% in home
Oysters safe to eat?
Very safe – 18.7%
Somewhat safe – 40.9%
Somewhat unsafe – 19.5%
Very unsafe – 7.1%
Don’t know – 13.7%

27. Descriptive Stats Male – 36.9% Statistically different Males
More likely to consume oysters
More likely to consume raw oysters
More likely to perceive oysters as safe to consume
More likely to consume oysters in a restaurant

28. Descriptive Stats Cooked and raw equally likely to cause illness?
No – 75.3%
Internet access – Yes – 55.2%
Source credibility – time spent on screen
No source – seconds
ISSC/FDA – seconds
Non-govt org – seconds