The distinction between complements, substitutes, and independent goods is important in many contexts. It is well known that when consumers' conditional indirect utilities for two goods are superadditive, the goods are gross complements. Generalizing insights in Gans and King (2006) and Gentzkow...

In systems industries, combinations of components are consumed together to generate user benefits. Arrangements among component providers sometimes limit consumers’ ability to mix and match components, and such exclusive arrangements have been highly controversial. We examine the competitive...