specifications, full incompatibility and preemption are again observed at the equilibrium. With incompatibility, entry deterrence …

consumers we establish see-saws between consumers and advertisers. Entry of a lower-quality platform increases consumer surplus …, but decreases advertiser surplus if industry platform profits decrease with entry. Merger decreases consumer surplus, but …

, including the relationship between the Herfindahl index and social welfare, free versus socially optimal entry, concentration …

consumers we establish see-saws between consumers and advertisers. Entry of a lower-quality platform increases consumer surplus …, but decreases advertiser surplus if industry platform profits decrease with entry. Merger decreases consumer surplus, but …

This article studies the design of optimal mechanisms to regulate entry in natural oligopoly markets, assuming the … that these mechanisms generally avoid budget deficits and prevent excessive entry. …

noninvesting firms. In each period, one investor can acquire a small firm, the other investor decides about market entry. After …

sufficiently high, license without entry strategy is optimum; if the low quality good’s quality is low, both of entry without … license strategy and license without entry strategy are optimum; when cost functions are quadratic, if the high quality good …’s quality is high, license without entry strategy is optimum; if the high quality good’s quality is low, entry with license …

, fails to draw on the most relevant fields of economics; entry is often a misanalyzed afterthought; official information …