The Economic Efficiency of Sampling Size: The Case of Beef Trim

Abstract

The economically optimal sample size in a food safety test balances the marginal costs and marginal benefits of increasing the sample size. We provide a method for selecting the sample size when testing beef trim for Escherichia coli O157:H7 that equates the averted costs of recalls and health damages from contaminated meats sold to consumers with the increased costs of testing while allowing for uncertainty about the underlying prevalence rates of contamination. Using simulations, we show that, in most cases, the optimal sample size is larger than the current sample size of 60 and, in some cases, it exceeds 120. Moreover, lots with a lower prevalence rate have a higher expected damage because contamination is more difficult to detect. Our simulations indicate that these lots have a higher optimal sampling rate.

Review of current methodologies to isolate and identify Campylobacter spp. from foods

“…In 2-class attributes sampling plan (presence/absence), the testing for the presence of a bacterial foodborne pathogen is done under the premise that the pathogen is not present in the sample. From the statistical standpoint, this premise (null hypothesis) signifies that the failure to find a pathogen when it is present is a Type II error and represents a false negative result (Ferrier and Buzby, 2013). Because the probability of finding a positive sample under this scheme is very low, and assuming that there are no methodological errors or artifacts, a Type I error (false positive) is reserved for the status of a sample after the first screening and from which no bacterial pathogen has been isolated after attempting a cultural confirmation.…”

Sample Size Allocation for Food Item Radiation Monitoring and Safety Inspection

“…The sample size (denoted by the number of samples throughout the article) for food safety inspection is a concern when managing food risk. For instance, the economically optimal sample size for inspections of beef trim potentially being contaminated with Escherichia coli O157:H7 remains debatable . The probability that food inspection will fail to detect contaminated samples increases with a decreasing sample size.…”

“…For instance, the economically optimal sample size for inspections of beef trim potentially being contaminated with Escherichia coli O157:H7 remains debatable. (18,19) The probability that food inspection will fail to detect contaminated samples increases with a decreasing sample size. However, sample sizes for inspections are generally limited by economic and practical costs, i.e., the number of personnel working and handling time during analysis.…”

Market impacts of E. Coli vaccination in U.S. Feedlot cattle

“…Costs include direct production costs such as additional labor requirements, slowing down processing line speed, investing in food safety technologies, modifying processing procedures or facilities, and expenses of more intensive product sampling and food safety testing (Ferrier and Buzby 2013). In face of a recall, costs of plant down-time, clean up, physical product losses, costs of completing a food recall, and loss of firm customers and reputation can collectively be substantial.…”

“…Because of the human health threat of E. coli, considerable beef industry and public health official efforts have targeted pathogen reduction in beef processing plants including development of extensive hazard analysis critical control points (HACCP) and intensive testing of beef for E. coli presence (Ferrier and Buzby 2013). Pre-harvest interventions to reduce pathogens in live cattle have arisen as one strategy to lessen chances of post-harvest bacterial contamination of beef.…”