Contestability and two-part pricing

This paper contributes to the debate over the relevance of contestability by demonstrating that the welfare properties claimed by proponents depend on the inability of incumbent firms to divide the market. Given the ability to divide the market using two-part prices, the incumbent can protect profitability. This possibility further illustrates the extremity of the assumptions upon which contestability rests as two-part pricing is commonly observed in some of the very markets that might be suggested to be more nearly contestable.The authors thank Barnali Gupta, William G. Shepherd and two reviewers for suggestions on earlier drafts.