Mary K. Muth

Certified kitchen managers: do they improve restaurant inspection outcomes?

Restaurants are associated with a significant number of foodborne illness outbreaks in the United States. Certification of kitchen managers through an accredited training and testing program may help improve food safety practices and thus prevent foodborne illness. In this study, relationships between the results of routine restaurant inspections and the presence of a certified kitchen manager (CKM) were examined. We analyzed data for 4461 restaurants in Iowa that were inspected during 2005 and 2006 (8338 total inspections). Using logistic regression analysis, we modeled the outcome variable (0 = no critical violations [CVs]; 1 = one or more CVs) as a function of presence or absence of a CKM and other explanatory variables. We estimated separate models for seven inspection categories. Restaurants with a CKM present during inspection were less likely to have a CV for personnel (P < 0.01), food source or handling (P < 0.01), facility or equipment requirements (P < 0.05), ware-washing (P < 0.10), and other operations (P < 0.10). However, restaurants with a CKM present during inspection were equally likely to have a CV for temperature or time control and plumbing, water, or sewage as were restaurants without a CKM present. Analyses by type of violation within the temperature and time control category revealed that restaurants with a CKM present during inspection were less likely to have a CV for hot holding (P < 0.05), but the presence of a CKM did not affect other types of temperature and time control violations. Our analyses suggest that the presence of a CKM is protective for most types of CVs, and we identify areas for improving training of CKMs.

A Test for Market Power Using Marginal Input and Output Prices With Application to the U.S. Beef Processing Industry

for a number of years, it has only been applied in rather limited ways. In this paper we show how this method can be used to develop a general test for oligopoly and oligopsony behavior. The test exploits the fact that, under price-taking behavior, there is a known, fixed relationship between changes in input prices on output supply and changes in output price on input demands. The model and test developed are shown to be quite general and not dependent on empirical estimates of output demand and input supply. We apply this test to the U.S. beef processing industry. Because of the high level of market concentration in this industry, there is concern that beef packing firms are exercising market power in the purchase of finished cattle by keeping cattle prices below competitive levels and in the sale of packed beef by keeping prices above competitive levels. Most previous studies of the beef packing industry have found evidence that firms, at least part of the time, are exercising market power in the purchase of finished cattle (Schroeter; Azzam and Pagoulatos; Schroeter and Azzam; Azzam; Azzam and Park; Koontz, Garcia, and Hudson) or are exercising market power in the sale of packed beef (Schroeter, Schroeter and Azzam). However, all of these studies are fairly restrictive in their assumptions regarding fixed proportions, the relationship between market power in the input and output markets, and the specification of input supply and output demand. Previous studies by Muth and by Muth and Wohlgenant (1999), which allow for variable proportions and do not impose restrictions on the relationship of market power in each market, did not find evidence of market power in the output and input markets for the beef packing industry; however, the results of each of these studies do depend on the specification of input supply and output demand.

Perceived stress, unhealthy eating behaviors, and severe obesity in low-income women

BackgroundStress has been associated with poor eating behaviors and diet quality, as well as high body mass index (BMI). Low-income women may be particularly vulnerable to stress and severe obesity. Yet it is unknown how stress increases the risk of severe obesity through disordered eating behaviors and poor diet quality or through mechanisms independent of diet.MethodsWe examined cross-sectional data from women (n = 101) with a child enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children in Cumberland County, North Carolina (spring 2012). We collected measured heights and weights to calculate BMI. Using structural equation modeling, we differentiated pathways from stress to weight status: (1) indirectly through eating behaviors (cognitive restraint, emotional eating, and uncontrolled eating) and diet quality, which we examined with the Healthy Eating Index 2010 and 24-h dietary recalls, and (2) directly through possible unmeasured risk factors independent of diet. The analysis controlled for race/ethnicity, income, age, whether the dietary recall day was typical, and whether the respondent completed one or two 24-h dietary recalls.ResultsPerceived stress was positively associated with uncontrolled eating (β = 0.38, p < 0.001) and emotional eating (β = 0.50, p < 0.001). However, higher stress was not associated with weight status through eating behaviors and diet quality. Independent of eating behaviors and diet quality, stress was positively associated with severe obesity (β = 0.26, p = 0.007).ConclusionsImproving stress coping strategies for low-income women may improve eating behaviors and reduce severe obesity.

A Novel Approach to Selecting and Weighting Nutrients for Nutrient Profiling of Foods and Diets

BACKGROUND Nutrient profiling of foods is the science of ranking or classifying foods based on their nutrient composition. Most profiling systems use similar weighting factors across nutrients due to lack of scientific evidence to assign levels of importance to nutrients. OBJECTIVE Our aim was to use a statistical approach to determine the nutrients that best explain variation in Healthy Eating Index (HEI) scores and to obtain β-coefficients for the nutrients for use as weighting factors for a nutrient-profiling algorithm. DESIGN We used a cross-sectional analysis of nutrient intakes and HEI scores. PARTICIPANTS Our subjects included 16,587 individuals from the National Health and Nutrition Examination Survey 2005-2008 who were 2 years of age or older and not pregnant. MAIN OUTCOME MEASURE Our main outcome measure was variation (R(2)) in HEI scores. STATISTICAL ANALYSES Linear regression analyses were conducted with HEI scores as the dependent variable and all possible combinations of 16 nutrients of interest as independent variables, with covariates age, sex, and ethnicity. The analyses identified the best 1-nutrient variable model (with the highest R(2)), the best 2-nutrient variable model, and up to the best 16-nutrient variable model. RESULTS The model with 8 nutrients explained 65% of the variance in HEI scores, similar to the models with 9 to 16 nutrients, but substantially higher than previous algorithms reported in the literature. The model contained five nutrients with positive β-coefficients (ie, protein, fiber, calcium, unsaturated fat, and vitamin C) and three nutrients with negative coefficients (ie, saturated fat, sodium, and added sugar). β-coefficients from the model were used as weighting factors to create an algorithm that generated a weighted nutrient density score representing the overall nutritional quality of a food. CONCLUSIONS The weighted nutrient density score can be easily calculated and is useful for describing the overall nutrient quality of both foods and diets.

The Fable of the Bees Revisited: Causes and Consequences of the U.S. Honey Program

In his 1973 paper, Steven Cheung discredited the “fable of the bees” by demonstrating that markets for beekeeping services exist and function well. Although economists heeded Cheung’s lessons, policy makers did not. The honey program has operated for over 50 years, supporting the price of honey through a variety of mechanisms. Its effects were minor before the 1980s but then became important, with annual government expenditures near

Effects of Post-Harvest Treatment Requirements on the Markets for Oysters

100 million for several years. Reforms of the program in the late 1980s reduced its market effects and budget costs, returning it to its original role as a minor commodity program. Although the 1996 Farm Bill formally eliminated the honey program, it was reinstated in the 2002 Farm Bill. We measure the historical welfare effects of the program during its various incarnations, examine its frequently stated public interest rationale—the encouragement of honeybee pollination—and interpret its history in light of economic theories of regulation.

Explaining Plant Exit in the U.S. Meat and Poultry Industries

Because of public health concerns, regulators are considering requiring post-harvest treatment of halfshell and shucked oysters by wholesalers and processors. Two recently developed post-harvest treatment technologies may actually reduce the costs of producing shucked oysters, but would increase the costs of halfshell oysters. An interregional model of the wholesale oyster industry is developed to estimate the effects of treatment requirements on prices, output, and employment. If post-harvest treatment is required for all Gulf oysters, price increases are estimated to be less than 20% and, in some cases, prices decrease. Results indicate producer and consumer losses in the halfshell market are partially or more than offset by gains in the shucked market.

The Value to Consumers of Health Labeling Statements on Breakfast Foods and Cereals

Recent U.S. pathogen reduction and HACCP food safety regulations, which increased the costs of producing meat and poultry products, may have affected the rate of plant exit during the 1996 to early 2000 time period over which the regulations were implemented. We estimate and compare probit models for U.S. federally inspected meat slaughter (920 plants), poultry slaughter (280 plants), and meat and poultry processing-only (4,300 plants) plants to determine which factors most contributed to the probability of plant exit. The factors we consider include plant-level, company-level, and regional-level characteristics and regional supply conditions. Although plant size affected the probability of exit for slaughter plants, it did not affect exit for processing-only plants. Other variables, such as measures of market structure and competition, have different effects for each of the industries.

Analysis of the Costs and Economic Feasibility of Requiring Postharvest Processing for Raw Oysters

Food manufacturers have an incentive to include nutrient content claims, health claims, or other types of labeling statements on foods if they believe that consumers will be willing to pay more for products with specific attributes. We estimated semi-log hedonic price regressions for five breakfast bar and cereal product categories using Nielsen Scantrack scanner data for 2004 and found that labeling statements for these foods are often associated with substantially higher prices, reflecting higher implicit value to consumers. The largest effects were associated with “carb-conscious” carbohydrate labeling (reflecting the time period of the data), followed by fat and sugar content labeling statements.

Analysis of the relationship between economic measures and Salmonella testing results in young chicken slaughter establishments.

 Because of concerns about Vibrio vulnificus, the U.S. Food and Drug Administration is considering requirements for postharvest processing (PHP) of oysters harvested from the Gulf of Mexico during warm-weather months and intended for raw consumption. As described in the paper, feasible PHP methods for warm-weather-harvested oysters include cool pasteurization, high hydrostatic pressure, and low-dose gamma-irradiation. We estimate that the costs of applying PHP are approximately 5 to 6 cents per half-shell oyster intended for raw consumption. However, most oyster processors have insufficient volumes to cost-effectively install PHP equipment. To assist these smaller operations, central PHP facilities operated by a 3rd party would be needed. A geographic information system analysis that minimized volume-weighted travel distances from each Gulf oyster operation identified 6 optimal PHP facility locations in the Gulf region. Even with the establishment of central PHP facilities, some oyster operations will become unprofitable and be at risk for closure.