This paper investigates the effects of demand information sharing on concession arrangements and market equilibria, when two ports, each managed by a welfare-maximizing port authority and a profit-maximizing port operator, compete for demands. The problem is formulated as a multi-stage game, in which the authority and the operator at each port first decide whether to share demand information and make concession arrangements; then, the port operators compete à la Cournot. Alternative scenarios are compared to identify the effects of information sharing and market structure. Our analytical results identify the conditions under which demand information sharing is beneficial in port concession arrangements and highlight the importance of the underlying market structure and congestion levels in achieving these benefits. Specifically, we show that information sharing is a source of welfare improvement, and the effects are more significant when the positive externality of information sharing on welfare is large, inter-port competition is strong, and port congestion is costly. However, with no compensation, the port operators have no incentive to share their private information because otherwise, this is likely to increase concession unit-fees, limit their ability to compete effectively with each other, and ultimately reduce their expected profits. Therefore, transfer payments are necessary to encourage information sharing. With this arrangement and the assumed symmetric cost and service structure, we show that a port operator prefers sharing information if the externality of information sharing on welfare exceeds a threshold. Furthermore, when this externality is sufficiently large, the operators at both ports benefit from sharing information. Finally, when the two ports compete in price, we show that a port operator's single-side information sharing may not always benefit its port authority.

本文研究了需求信息共享对特许权安排和市场均衡的影响，当两个港口分别由福利最大化的港口管理局和利润最大化的港口运营商管理时，竞争需求。问题被表述为一个多阶段博弈，其中每个港口的主管部门和运营商首先决定是否共享需求信息并做出让步安排；然后，港口运营商将与古诺竞争。比较替代方案以识别信息共享和市场结构的影响。我们的分析结果确定了需求信息共享在港口特许权安排中有利的条件，并强调了基础市场结构和拥堵程度对实现这些利益的重要性。特别，我们表明，信息共享是改善福利的一个源泉，当信息共享对福利的积极外部性很大，端口间竞争很激烈且港口拥堵成本高昂时，其影响会更大。但是，在没有补偿的情况下，港口经营者没有动力共享他们的私人信息，因为否则，这可能会增加特许单位费，限制他们有效竞争的能力，并最终降低其预期利润。因此，转移支付对于鼓励信息共享是必要的。通过这种安排以及假定的对称成本和服务结构，我们表明，如果关于福利的信息共享的外部性超过阈值，则港口运营商更愿意共享信息。此外，当这种外部性足够大时，两个端口的运营商都将从共享信息中受益。最后，当两个港口在价格上竞争时，我们证明了港口运营商的单方面信息共享可能并不总是使其港口当局受益。