Theil's theory of rational random errors is sufficient for strict exogeneity of group expenditure in separable demand models. Generalized rational random errors is necessary and sufficient for strict exogeneity of group expenditure. A simple, robust, asymptotically normal t-test of this...

Gorman Engel curves are extended to incomplete systems. The roles of Slutsky symmetry and homogeneity/adding up are isolated in the rank and functional form restrictions for Gorman systems. Symmetry determines the rank condition. The maximum rank is three for incomplete and complete systems....

A flexible, full rank two model of food consumption that is globally consistent with economic theory, aggregates across income, demographic variables, and variations in micro demand parameters, and accommodates tradeoffs between tastes and nutrition is derived. The econometric demand model is...

An econometric model of annual per capita U.S. food and nutrition demand is developed. The model is a flexible, full rank two Gorman polar form. It is strictly aggregable across income, demographic variables, and variations in micro preference parameters. Parametric conditions for global...

Diminishing marginal utility(DMU)is neither necessary nor sufficient for downward sloping demand. Yet upper-division undergraduate and beginning graduate students often presume otherwise. This paper provides two simple counter examples that can be used to help students understand that the Law of...

A partial equilibrium model of stochastic crop production is used to analyze the environmental impacts of popular subsidized crop insurance programs. Land use is unchanged only when an actuarially fair, perfectly separating insurance contract is offered. For the more typical pooling equilibrium...

Livestock grazing on public lands continues to be a source of intense conflict and debate. We analyze this problem using a dynamic game. Low grazing fees let ranchers capture more rent from grazing. This increases the incentive to comply with federally mandated regulations. Optimal grazing...