Uniform Substitutes When Group Preferences are Blockwise Dependent

This paper extends the uniform substitutes model developed by Theil (1980) in a block independent framework to one derived in a blockwise dependent framework. The approach is developed in the case of the demand for different brands of the same good. The uniform substitutes preference structure is nested under weakly separable preferences and the restrictions can be tested statistically with a log likelihood ratio test. Conditional expenditure and price elasticities are derived for uniform substitutes.