We consider dynamic competition among platforms in a market with network externalities. A platform that dominated the market in the previous period becomes "focal" in the current period, in that agents play the equilibrium in which they adopt the focal platform whenever such equilibrium exists....

In this chapter, we discuss economic aspects of cryptocurrencies. 4.1. The double spending problem 4.2. How does Bitcoin work? Brief overview 4.3. Not the first one – predecessors of Bitcoin 4.4. Problems with Bitcoin (new challenges) 4.5. Competition against other crypto-currencies 4.6....