Information Spillovers Across Media Markets: Risk Perceptions and Cyclospora Outbreaks in U.S. Bagged Salads

From 2018 to 2022, contamination of fresh produce by Cyclospora cayetanensis, primarily affecting bagged salads, caused more than 3,300 outbreak-associated illnesses across the United States. Yet the economic consequences of these outbreaks, and the role of information exposure in shaping consumer responses, remain poorly understood. This study quantifies changes in bagged salad purchases and associated retail losses during six selected large multistate outbreaks occurring from 2018 to 2022 and examines how risk perceptions evolve across outbreak-affected and neighboring regions. Guided by a risk perception framework emphasizing risk proximity and information-driven belief updating, we integrate epidemiologic outbreak data, designated market area (DMA)-level Google Trends search intensity as a geographically granular proxy for information exposure, and NielsenIQ household purchase data. Because DMAs often cross state lines, this design identifies information spillovers to non-outbreak states sharing a media market. A Heckman selection framework accounts for purchase participation and unobserved heterogeneity, while complementary retail scanner data assess whether retailer stocking adjustments contributed to the observed purchase declines. Across the outbreak periods examined in this study, weekly bagged salad purchases declined by an average of 3.89%, implying cumulative retail losses of approximately $373.67 million. Outbreak-specific searches (e.g., "Cyclospora") were associated with greater perceived risk and larger purchase reductions, while general salad-related searches were associated with smaller reductions. Spillovers across shared media markets further reduced purchases in non-outbreak states by 3.33% per week. Retailer analysis found no statistically significant store-level stocking reductions during outbreak or recall periods, supporting the interpretation that the observed purchase declines were primarily demand-driven. These findings highlight the economic significance of information-driven consumer responses and the importance of timely, accurate, and geographically targeted risk communication during foodborne outbreaks.