The interest in marketing margins and price transmission has recently gained remarkable momentum and the amount of studies on this subject is rapidly growing. There is a myriad of questions about prices and margins investigated by these studies, yet new questions are surfacing as markets and business practices change with an impressive speed. Wohlgenant (2001), in his survey on marketing margins, identifies some of the questions puzzling researchers and policy makers alike. For example: Are marketing margins too large? Why are margins different among products? How have...