Prices Before and After Vertical Mergers of Firms

It is well known that a commodity which is sold by a producer P to a sales firm S before it becomes available to consumers, may cost consumers more than in the case in which the two firms merge; in this connections see, e.g., Weintraub (1949), Niehans (1959), Eichhorn (1973), Funke (1977), Eichhorn and Funke (1977).