雙占競爭下的下一代網路接續定價及投資

Access Pricing and Investment in Next-Generation Networks under Duopolistic Competition

本文分析一種新的投資繞過（bypass）賽局，在不同的接續定價政策下，既存廠商和新進廠商要決定究竟是升級到下一代網路（NGN），或停留在舊一代網路。有一個完全整合的既存廠商在吸引顧客方面比新進廠商更有優勢，且兩家廠商都在差異化服務市場做價格競爭。收入中立管制下，既存廠商投資NGN並為新進廠商提供接續的策略組合始終是Nash均衡，這或導致過度行動（excess momentum）。在既存廠商未投資的情況下，也存在繞過均衡，這或讓既存廠商有過度惰性（excess inertia）。Ramsey政策建議對接續價格進行多種設計，以彌補可能的低效率。兩個關於網路外部性和轉換成本的延伸驗證了模型的穩健性。

This paper analyzes a novel investment and bypassing game where an incumbent and an entrant either upgrade to a next-generation network (NGN) or stay in the old generation network under different access pricing policies. There is a fully integrated incumbent who has an advantage over the entrant in attracting customers, and both firms engage in price competition in the differentiated service market. Under revenue-neutral regulation of access prices, the strategy combination in which the incumbent invests in an NGN with the provision of access to the entrant is always a Nash equilibrium, which may lead to excess momentum. There also exists a bypassing equilibrium without the investment from the incumbent, which may present excess inertia for the incumbent. The Ramsey policy suggests diverse designs on access prices to remedy the possible inefficiency. We also provide two extensions on network externality and switching costs for robustness.