Compatibility and Market Structure for Network Goods

This paper analyzes the economics of industries where network externalities are significant. In such industries, firms have strong incentives to adhere to common technical compatibility standards, so that they reap the network externalities of the whole group. However, a firm also benefits from producing an incompatible product thereby increasing its horizontal product differentiation. We show how competition balances these opposing incentives. We find that market equilibria often exhibit extreme disparities in sales, output prices, and profits across firms, despite no inherent differences in the firms' production technologies. This may explain the frequent domination of network industries by one or two firms. We also find that the presence of network externalities dramatically affects conventional welfare analysis, as total surplus in markets where these externalities are strong is highest under monopoly and declines with entry of additional firms.