Launhardt模型與差別取價下的內生區位選擇

Launhardt Model, Discriminatory Pricing and Endogenous Location Choice

對廠商的競爭而言，垂直產品差異化與水平產品差異化是兩項主要考量的方向。本文將廠商差別取價的行為納入分析，討論廠商同步進入市場與依序進入市場兩種結構下的產品差異化行為。當廠商同步進入市場，垂直產品差異化程度與廠商水平差異化程度無關。當廠商依序進入市場時，先佔優勢將影響區位選擇。效率較差廠商先進入市場時，垂直產品差異將會影響水平產品差異的大小。當晚進入市場的廠商有顯著的效率優勢時，垂直產品差異將擴大水平產品差異；但若先後進入廠商效率差異不大時，垂直產品差異會對水平產品差異有負向效果。

Vertical product differentiation and horizontal product differentiation have long been recognized as key factors of firms’ competition. Ferreira and Thisse (1996) shows that when two firms compete in both horizontal product differentiation and vertical product differentiation, and there’s no price discrimination, subgame perfect Nash equilibria have the property that the extent of vertical product differentiation negatively related to the degree of horizontal product differentiation. The present paper shows that, in an oligopoly market, instead of single price competition, when firms compete with discriminatory pricing, the relation between vertical and horizontal product differentiation is determined by the order of entry. When firms choose location simultaneously, the extent horizontal differentiation is unrelated to the extent of vertical differentiation, and when firms enter sequentially, the extent of vertical product differentiation might positively relate to the degree of horizontal product differentiation.