Both sides of a two-sided market are usually modeled as markets without product differentiation. Often however, it will be profit maximizing to differentiate one or two sides in two or more types. In a simple theoretical model, inspired by Yellow Pages, we show that this decision crucially...

Europe's dependence on Russian gas imports has been the subject of increasing political concern after gas conflicts between Russia and Ukraine in 2006 and 2009. This paper assesses the potential impact of Russian unreliability on the European gas market, and how it affects European gas import...