We examine the impact of the licensing policies of one or more upstream owners of essential intellectual property (IP hereafter) on the variety offered by a downstream industry, as well as on consumers and social welfare. When an upstream monopoly owner of essential IP increases the number of...

The paper makes two related contributions. First, and in contrast with the rich body of literature on collusion with (mainly perfect) substitutes, it derives general results on the sustainability of tacit coordination for a class of nested demand functions that allows for the full range between...