Credible Spatial Preemption
指出，当多产品在位企业可能因进入而退出时，先占性投资反而会鼓励进入，使市场更不易形成垄断，替代性越强、退出成本越低、竞争越激烈时越明显。
It is often argued that incumbent firms may deter entry by preemptive investment in new goods. We show that these conclusions are reversed when multiproduct incumbentfirms may exit in response to entry. Once entrants are in an industry, an incumbent will often want to withdraw some goods to prevent competition with the entrant from reducing profits on other goods. Such a reaction makes entry more attractive to a potential entrant. The equilibrium industry structure is less likely to be monopolistic as the goods are better substitutes, as exit costs are low, and as the competition between producers of the same good is more intense.