Quadratic Differential Demand Systems and the Retail Demand for Pork in Great Britain
推导了一个通用的二次微分需求系统，并用于分析1989-2000年间英国猪肉零售需求，发现二次AIDS模型最适合，但二次支出项并非对所有猪肉切块都必要。
The primary objective of this paper is to derive a general synthetic quadratic (rank 3) differential demand system which nests within it a range of testable differential demand models including the quadratic AIDS, CBS, Rotterdam and NBR systems. A model selection test procedure is also outlined. These differential systems are then applied and tested to analyse the monthly retail demand for cuts of pork in Great Britain over the period 1989–2000. The empirical results suggest that a quadratic differential AIDS model is most appropriate for the pork demand system studied, but that the need for inclusion of quadratic income/expenditure terms is not universal for every cut within the demand system. Quadratic expenditure effects were appropriate for pork chops and leg roasts, but log linear expenditure effects were adequate for bellies, shoulders and loin roasts. Roasting cuts were expenditure and own price elastic, with pork loins, chops and bellies all expenditure and own price inelastic.