Retailers may enjoy stable cartel rents in their output market through the formation of a buyer group in their input market. A buyer group allows retailers to credibly commit to increased input prices, which serve to reduce combined final output to the monopoly level; increased input costs are...

Antitrust and competition law have grown dramatically in importance and significance over the last fifty years. US antitrust law has been the principal source of inspiration for jurisdictions wishing to introduce regulation to control cartels and monopolization, and antitrust regulation has now...

We characterize collusion involving secret vertical contracts between retailers and their supplier – who are all equally patient ("vertical collusion"). We show such collusion is easier to sustain than collusion among retailers. Furthermore, vertical collusion can solve the supplier's...

Under ex ante access regulation entrants often claim that access fees are excessive. I show that this is only the case if further entry is admitted. If the entrant is protected from further entry it would agree with the incumbent upon a strictly positive access fee which may exceed the efficient...

In recent years, South African competition authorities have initiated a number of price-fixing cases in markets where cooperation among competitors was legal and often encouraged. These markets present economists with special difficulties when estimating cartel overcharges. Conventional...

This paper assesses the antitrust fines and private penalties imposed on the participants of 260 international cartels discovered during 1990-2005, using four indicators of enforcement effectiveness. First, the United States is almost always the first to investigate and sanction international...

This is a survey of the economic principles that underlie antitrust law and how those principles relate to competition policy. We address four core subject areas: market power, collusion, mergers between competitors, and monopolization. In each area, we select the most relevant portions of...

In industries with unobservable wholesale contracting, retailers may enjoy cartel rents in their output market through the formation of a buyer group in their input market. A buyer group allows retailers to credibly commit to increased input prices, which serve to reduce combined final output to...

We investigate the effect of a vertical merger on downstream firms' ability to collude in a repeated game framework. We show that a vertical merger has two main effects. On the one hand, it increases the total collusive profits, increasing the stakes of collusion. On the other hand, it creates...

We consider a vertically related industry and analyze how the total harm due to a price increase upstream is distributed over downstream firms and final consumers. For this purpose, we develop a general model without making specific assumptions regarding demand, costs, or the mode of...