本文假設一家上游廠商與兩家生產異質產品的下游廠商之垂直相關市場結構，研究內生化市場結構與中間財定價策略。研究結果發現，在給定垂直整合相關市場下，當產品替代性較小時，垂直整合廠商選擇中間財的固定費用定價策略；當產品替代性較大時，則選擇中間財的單位定價策略。在給定垂直分離相關市場下，當產品替代性較小時，上游廠商選擇固定費用定價策略，將中間財販售給兩家下游廠商；當產品替代性較大時，則選擇固定費用定價策略，將中間財販售給單獨一家下游廠商。在考慮內生化市場結構下，研究結果發現，當產品替代性較小時，上游廠商選擇與任一家下游廠商合併或是選擇不合併；當產品替代性適中時，上游廠商不會選擇合併，並採用固定費用定價策略，將中間財販售給兩家下游廠商；當產品替代性較大時，上游廠商選擇與任一家下游廠商合併，並選擇中間財的單位定價策略。

This research investigates the endogenous choice of market structure and input pricing strategy by taking into account a vertically-related market where an upstream firm sells an intermediate good to two downstream firms that produce horizontally-differentiated products. For a given verticallyrelated market with vertical integration, the integrated firm chooses a fixedfee pricing strategy (a per-unit pricing strategy) when the degree of product substitutability is relatively low (high). For a given vertically-related market with vertical separation, the upstream firm offers input to both downstream firms (one downstream firm) via a fixed-fee pricing strategy when the degree of product substitutability is relatively low (high). When both the market structure and input pricing strategy are endogenously determined, we find when the degree of product substitutability is relatively low that one of the two downstream firms merges with the upstream firm or neither of the downstream firms merge with the upstream firm. When the degree of product substitutability is relatively moderate, neither of the downstream firms merge with the upstream firm. When the degree of product substitutability is relatively high, one of the two downstream firms merges with the upstream firm.