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....

We analyse the effects of investment decisions and firms internal organisation on the efficiency and stability of horizontal mergers. In our framework economies of scale are endogenous and there might be internal conflict within merged firms. We show that often stable mergers do not lead to more...