Consumers are different in their purchase rates and it is important to determine this heterogeneity. If a consumer's purchases follow a Poisson process (hence exponential interpurchase time), and purchase rates are distributed gamma across consumers, then a simple measure of heterogeneity is the...

A one-to-one map between a specific demand structure and a restricted cross-elasticity matrix is developed and tested using a random utility model. The resulting demand structure can be used to evaluate a firm's ability to differentiate its products, and can help determine if demand is...