George C. Davis

Food Waste in a School Nutrition Program After Implementation of New Lunch Program Guidelines

OBJECTIVE To assess the amount of food waste by meal components according to the new National School Lunch Program guidelines among pre-kindergarten and kindergarten students. METHODS For 5 consecutive school days in 1 elementary school, the research team collected school lunch trays and separated meal components into bins relative to each food or beverage appearing on the schools daily menu. Bins were weighed in grams and converted to ounces and cups at the end of each lunch period. RESULTS The researchers examined 304 meals from 1 pre-kindergarten class and 5 kindergarten classes. Of 4,988 oz of food and beverages served, 2,261 oz (45.3%) were wasted during 1 full school week, totaling 141 lb. The greatest amount of food waste was generated from vegetables, the main entree, and milk, respectively. CONCLUSIONS AND IMPLICATIONS Strategies to reduce food waste in school lunch should be researched and implemented.

The Theory and Econometrics of Health Information in Cross-Sectional Nutrient Demand Analysis

Understanding the role of health information in food and nutrient demand has become an important issue over the last decade. Endogeneity and measurement error are two empirical problems that are inherent in this type of analysis. While some type of instrumental variables estimation would appear the obvious solution, this paper provides several theoretical and empirical reasons why this is not the case in cross-sectional analysis. An alternative estimation strategy is pursued, an empirical example given, and the implications discussed.

The Logic of Testing Structural Change in Meat Demand: A Methodological Analysis and Appraisal

In the past two decades, the profession has expended valuable resources testing structural change in meat demand with mixed results. Overlooked to date is a fundamental methodological problem that transcends all methods of testing for structural change. In this study, a methodological framework is used to show that there is no valid test of structural change. Because of this result, additional criteria from the methodology literature are used to evaluate the literature on structural change in meat demand and to provide suggestions for fertile areas of future research. Copyright 1997, Oxford University Press.

Measuring Substitution in Monetary-Asset Demand Systems

The Allen elasticity of substitution (AES) is widely used to study monetary-asset substitution and structural demand stability. Blackorby and Russell showed that the AES is uninformative and that the Morishima elasticity of substitution (MES) is the appropriate measure, a point overlooked in the monetary literature. Use of improper measures can lead to incorrect inferences. This article considers five alternative measures of substitution—the AES, the MES, the Hicksian and Marshallian elasticities of demand, and Mundlaks unencountered, but appealing, constant-cost elasticity of substitution. Selection of the substitution measure appropriate to respective research questions is addressed.

Consistent Estimation of Armington Demand Models

Traditional methods of empirically implementing the popular Armington trade model are shown to result in theoretically and statistically inconsistent parameter estimates. A method for removing these inconsistencies within the framework of the Armington model is provided, along with a comparison of results of our new consistent procedure with those of the previous procedure.

The Thrifty Food Plan Is Not Thrifty When Labor Cost Is Considered

Recent research has shown that the typical Supplemental Food Assistance Program (SNAP) family falls short in meeting the Thrifty Food Plan (TFP) nutritional guidelines that underlie the SNAP even when they typically have sufficient monetary resources to eat a healthful diet (i.e. to follow the TFP recommendations). However, the TFP does not consider labor cost. This study uses a basic labor economics technique to value labor in a home food production scenario that is required to reach the TFP nutrition and budget targets and calculates the total cost (inclusive of labor) associated with the TFP. This TFP consistent total cost is then compared, using several metrics, with the total cost associated with actual choices made by those families sharing the same profiles as current SNAP participants. Once labor is included, we find the TFP is not very thrifty and the mean household falls short of the TFP guidelines even with adequate monetary resources.

The time cost of food at home: general and food stamp participant profiles

Little is known about the cost of time in food preparation at home. Yet, this economic variable is a common thread running through recent concerns about obesity and the Food Stamp (FS) program. This article provides initial estimates of the time cost in food preparation at home for the United States. Two standard methods of estimation are implemented and three demographic profiles are considered: (i) the general population, (ii) the typical FS participant and (iii) the typical FS participant following the United States Department of Agriculture Thrifty Food Plan. For the general population and averaging across methods, the time cost share of total food cost is about 30% if the individual works in the market and at home, but it is about 49% if the individual does not work in the market. For the typical FS participant, especially one following the Thrifty Food plan, the time cost share of total food cost can be as much as 26% higher than the general population. These substantial percentages provide strong incentives to purchase food away from home and help undermine overall diet quality and the efficacy of the FS program, which ignores the time cost in food at home production.

DOES CONSISTENT AGGREGATION REALLY MATTER

Consistent aggregation ensures that behavioural properties which apply to disaggregate relationships apply also to aggregate relationships. The agricultural economics literature which has tested for consistent aggregation or measured statistical bias and/or inferential errors due to aggregation is reviewed. Tests for aggregation bias and errors of inference are conducted using indices previously tested for consistent aggregation. Failure to reject consistent aggregation in a partition did not entirely mitigate erroneous inference due to aggregation. However, inferential errors due to aggregation were small relative to errors due to incorrect functional form or failure to account for time series properties of data.

Aggregation without Separability: Tests of the United States and Mexican Agricultural Production Data

The generalized composite commodity theorem (GCCT) and testing procedure is extended to test for consistent aggregation of the United States and Mexican agricultural production data in each category for which earlier tests rejected homothetic separability. Nonrejected GCCT and separability hypotheses provide empirical support for aggregating all the United States agricultural outputs into as few as two categories: crops and livestock. Mexican agricultural outputs also can be aggregated into as few as two categories. Support for aggregating all outputs into a single category is ambiguous in both countries and is only provided by the GCCT. Copyright 2000, Oxford University Press.

Product Aggregation Bias as a Specification Error in Demand Systems

Inherent in all demand studies is some form of product aggregation which can lead to product aggregation bias. This article develops a simple procedure for incorporating product aggregation bias in demand systems that permits testing of product aggregation bias with a standard likelihood ratio test. An empirical illustration of the procedure demonstrates the importance of proper product aggregation. Copyright 1997, Oxford University Press.