The sales-marketing mix relationships for brands of a product class are often modelled as a multiple equation system. Whenever sales are expressed as shares, such systems are sum-constrained and therefore singular. Singular systems can be calibrated by deleting one equation from the model and...

Since the papers of Basu et al. (1985) and Lal and Srinivasan (1993), marketing academics have been interested in the design and implementation of optimal compensation plans. The literature has focused on agency theory as a foundation to help describe and understand this process. Although there...