直線型城市下的先發制人賽局

Preemption in a Linear City

本文在直線型城市的空間差別定價模型下，研究廠商的區位與進入市場時點競爭。在Fudenberg and Tirole（1985）所提出之先發制人賽局（pre-emption game）架構下，假設廠商先決定其進入市場的時點與區位，在廠商進入市場後，決定其在每個時點，在直線型城市上所有市場的數量或價格。研究發現，無論是在Cournot競爭或Bertrand競爭之下，雙占廠商依序進入市場，其中領導廠商座落在直線型城市的端點，而跟隨廠商座落在城市內部是唯一的均衡型態，而均衡時雙占廠商利潤折現和相等。隨著運輸費率上升，在Cournot競爭之下，雙占廠商區位差異上升；而在Bertrand競爭之下，雙占廠商區位差異下降。在Bertrand競爭之下，雙占廠商的區位差異與時點差異，皆大於Cournot競爭之下，雙占廠商的區位差異與時點差異。

Based on Fudenberg and Tirole's (1985) preemption game, this study investigates both the theory of endogenous location and the timing of entry in a spatial discrimination model with a linear city. Two firms first decide when to enter the market and where to locate their respective plant and then compete in price or quantity in the product market at each instance. We find that the equilibrium involves sequential entry, with the leader locating at one endpoint and the follower locating in the interior of the linear city. The location differentiation in the Cournot model is increasing in transportation cost, whereas in the Bertrand model it is decreasing. The location differentiation and timing differentiation are both larger under Bertrand competition than under Cournot competition.