{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/109667"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/109667","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Effects of Food Safety Events on U.S. Romaine Lettuce Prices","abstract":"Romaine lettuce and leafy greens have been at the center of food safety concerns over the last several years. More specifically, romaine lettuce has been directly linked to seven(7) foodborne illness outbreaks and resulted in five(5) recalls over the eight(8) years period of January 1, 2012, to December 31, 2019. This paper estimates the effects that these food safety events have had on the price returns of romaine lettuce utilizing a series of Generalized Autoregressive Conditional Heteroskedasticity (GARCH) models. Importantly, the GARCH models allowed us to capture the effects of the recall and illness outbreaks on both the returns and volatility of the romaine price series. We find that three (3) of the seven (7) illness outbreaks resulted in marked increases in the price returns - between 4.1% and 9.6%. Conversely, three (3) of the five (5) recalls reduced price returns - between 30% and 57%. However, the volatility is not found to be significantly nor to affect the price volatility significantly. We conclude that recalls serve as a market correction in the romaine lettuce market. Consequently, a continued focus on increasing traceability with in the romaine lettuce market will help to reduce price fluctuation and limit the number of illnesses resulting from outbreaks.","abstract_html":"Romaine lettuce and leafy greens have been at the center of food safety concerns over the last several years. More specifically, romaine lettuce has been directly linked to seven(7) foodborne illness outbreaks and resulted in five(5) recalls over the eight(8) years period of January 1, 2012, to December 31, 2019. This paper estimates the effects that these food safety events have had on the price returns of romaine lettuce utilizing a series of Generalized Autoregressive Conditional Heteroskedasticity (GARCH) models. Importantly, the GARCH models allowed us to capture the effects of the recall and illness outbreaks on both the returns and volatility of the romaine price series. We find that three (3) of the seven (7) illness outbreaks resulted in marked increases in the price returns - between 4.1% and 9.6%. Conversely, three (3) of the five (5) recalls reduced price returns - between 30% and 57%. However, the volatility is not found to be significantly nor to affect the price volatility significantly. We conclude that recalls serve as a market correction in the romaine lettuce market. Consequently, a continued focus on increasing traceability with in the romaine lettuce market will help to reduce price fluctuation and limit the number of illnesses resulting from outbreaks.","abstract_has_math":false,"creators":["Adams, Normand Rutledge"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Agricultural and Applied Economics","degree_department":"Agricultural and Applied Economics","school":null,"contributors":[],"advisors":[],"committee_chairs":["Neill, Clinton L.","Stewart, Shamar L."],"committee_members":["Holt, Matthew T."],"year":2020,"date_issued":"2020-10-21","date_published":"2020-10-21","updated_at":"2026-07-22T22:19:13Z","subjects":["Food Recall","Illness","Food Safety","Romaine","GARCH"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:27675"],"render_values":[{"text":"vt_gsexam:27675","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/109667","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Neill, Clinton L.","Stewart, Shamar L."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Holt, Matthew T."]},{"key":"dc:contributor.department","label":"Department","values":["Agricultural and Applied Economics"]},{"key":"dc:creator","label":"Author","values":["Adams, Normand Rutledge"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2022-04-15T06:00:07Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-04-15T06:00:07Z"]},{"key":"dc:date.issued","label":"Date","values":["2020-10-21"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Agricultural and Applied Economics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Food Recall","Illness","Food Safety","Romaine","GARCH"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:27675"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/109667"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Romaine lettuce and leafy greens have been at the center of food safety concerns over the last several years. More specifically, romaine lettuce has been directly linked to seven(7) foodborne illness outbreaks and resulted in five(5) recalls over the eight(8) years period of January 1, 2012, to December 31, 2019. This paper estimates the effects that these food safety events have had on the price returns of romaine lettuce utilizing a series of Generalized Autoregressive Conditional Heteroskedasticity (GARCH) models. Importantly, the GARCH models allowed us to capture the effects of the recall and illness outbreaks on both the returns and volatility of the romaine price series. We find that three (3) of the seven (7) illness outbreaks resulted in marked increases in the price returns - between 4.1% and 9.6%. Conversely, three (3) of the five (5) recalls reduced price returns - between 30% and 57%. However, the volatility is not found to be significantly nor to affect the price volatility significantly. We conclude that recalls serve as a market correction in the romaine lettuce market. Consequently, a continued focus on increasing traceability with in the romaine lettuce market will help to reduce price fluctuation and limit the number of illnesses resulting from outbreaks."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Romaine lettuce and leafy greens have been at the center of food safety concerns over the last several years. More specifically, romaine lettuce has been directly linked to 7 foodborne illness outbreaks and resulted in 5 recalls over the eight years, January 1, 2012, to December 31, 2019. This paper estimates the effects that these food safety events have had on the price returns of romaine lettuce. It was found that 3 of the seven illness outbreaks resulted in marked increases in the price returns - between 4.1% and 9.6% while, 3 of the 5 recalls reduced price returns - between 30% and 57%. However, the volatility is not found to be significantly nor to affect the price volatility significantly. It is concluded that recalls serve as a market correction in the romaine lettuce market. A continued focus on increasing traceability with in the romaine lettuce market will help to reduce price fluctuation and limit the number of illnesses resulting from outbreaks."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Effects of Food Safety Events on U.S. Romaine Lettuce Prices"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Neill, Clinton L.","Stewart, Shamar L."],"dc:contributor.committeemember":["Holt, Matthew T."],"dc:contributor.department":["Agricultural and Applied Economics"],"dc:creator":["Adams, Normand Rutledge"],"dc:date.accessioned":["2022-04-15T06:00:07Z"],"dc:date.available":["2022-04-15T06:00:07Z"],"dc:date.issued":["2020-10-21"],"dc:description.abstract":["Romaine lettuce and leafy greens have been at the center of food safety concerns over the last several years. More specifically, romaine lettuce has been directly linked to seven(7) foodborne illness outbreaks and resulted in five(5) recalls over the eight(8) years period of January 1, 2012, to December 31, 2019. This paper estimates the effects that these food safety events have had on the price returns of romaine lettuce utilizing a series of Generalized Autoregressive Conditional Heteroskedasticity (GARCH) models. Importantly, the GARCH models allowed us to capture the effects of the recall and illness outbreaks on both the returns and volatility of the romaine price series. We find that three (3) of the seven (7) illness outbreaks resulted in marked increases in the price returns - between 4.1% and 9.6%. Conversely, three (3) of the five (5) recalls reduced price returns - between 30% and 57%. However, the volatility is not found to be significantly nor to affect the price volatility significantly. We conclude that recalls serve as a market correction in the romaine lettuce market. Consequently, a continued focus on increasing traceability with in the romaine lettuce market will help to reduce price fluctuation and limit the number of illnesses resulting from outbreaks."],"dc:description.abstractgeneral":["Romaine lettuce and leafy greens have been at the center of food safety concerns over the last several years. More specifically, romaine lettuce has been directly linked to 7 foodborne illness outbreaks and resulted in 5 recalls over the eight years, January 1, 2012, to December 31, 2019. This paper estimates the effects that these food safety events have had on the price returns of romaine lettuce. It was found that 3 of the seven illness outbreaks resulted in marked increases in the price returns - between 4.1% and 9.6% while, 3 of the 5 recalls reduced price returns - between 30% and 57%. However, the volatility is not found to be significantly nor to affect the price volatility significantly. It is concluded that recalls serve as a market correction in the romaine lettuce market. A continued focus on increasing traceability with in the romaine lettuce market will help to reduce price fluctuation and limit the number of illnesses resulting from outbreaks."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:27675"],"dc:identifier.uri":["http://hdl.handle.net/10919/109667"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Food Recall","Illness","Food Safety","Romaine","GARCH"],"dc:title":["Effects of Food Safety Events on U.S. Romaine Lettuce Prices"],"dc:type":["Thesis"],"thesis:degree_discipline":["Agricultural and Applied Economics"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:13Z"}