The pattern of demand in the United States.

The objective of this paper is to examine the demand for goods and services in the United States using the Almost Ideal Demand System (AIDS). The focus is on testing the theoretical properties of demand. The model fits the data well. The suggestion is that food, clothing, housing and transportation are necessities while medical care and recreation are luxuries. The notion of homogeneity is generally accepted while symmetry is soundly rejected. Finally, negativity is shown to hold.