Shi, Hongqi

July, 1998

By: Shi, Hongqi; Price, David W.
The implicit values of nutrient and nonnutrient characteristics of breakfast cereal were estimated using the 1987-88 household portion of the USDA's Nationwide Food Consumption Survey data. The effects of sociodemographic variables on cereal characteristic values were also estimated. The conceptual framework of the hedonic price model, used for food products, has traditionally focused on the nutritional characteristics of these products. This framework was extended to incorporate nonnutritional characteristics. Findings indicate that consumers' sociodemographic characteristics significantly affect the implicit values of both nutritional and nonnutritional cereal characteristics. Results generally met with prior expectations.

December, 1996

By: Mittelhammer, Ronald C.; Shi, Hongqi; Wahl, Thomas I.
This study revisits the consistent aggregation (over households) property of almost ideal demand system (AIDS) models and presents a method to explicitly account for expenditure aggregation bias when estimating the aggregate AIDS model with time-series data. Ignoring aggregation bias can lead to biased and inconsistent parameter estimates and can cause aggregate demand functions to be inconsistent with the demand functions at the individual household level. Recognizing the general limited information contained in aggregate time-series data for explicitly modeling aggregation bias, we present a new method of constructing an aggregation bias term that is derived from the proportions of household in different income groups. This information is generally available in developed economies. We use this framework to estimate aggregate meat demand within a complete demand system based on U.S. annual expenditure data.