價格競爭下的訊號反轉

在傳統文獻中，在訊息不完全的情況下，生產高品質產品之廠商可以藉由價格、廣告等方式，傳遞關於其產品品質的訊息給消費者。但透過價格的訊號傳遞，在獨佔市場下，價格的扭曲會造成高品質廠商利潤的減少。因此，在不完全訊息下，獨佔廠商的利潤會低於完全訊息下之利潤。本文假設在寡佔市場下，討論廠商利如何用價格作為傳遞商品品質的訊號，本文首先分析分離均衡存在的必要條件。其次，進一步討論滿足均衡的充分參數條件，並進一步比較訊息不完全下廠商利潤的變化情形。本文發現，在特定條件下，在不完全訊息下廠商的利潤會大於完全訊息下之利潤。

關鍵字

訊號傳遞；價格競爭；訊號反轉

並列摘要

In the traditional literature, under incomplete information, the high quality firm can signal its product quality by a high price or advertising. In signaling situation, the distortion of the price will reduce the profit and therefore the profit of the monopolist firm, under incomplete information, will be lower than that in complete information. In this research, we consider a duopoly market in which a new entrant firm engages in price competition with an established firm. Both firms know the product quality of each other perfectly, while consumers are not informed about the product quality of the entrant firm. We first characterize the necessary conditions of the separating equilibria. Then, we discuss the parameter conditions that ensure the existence of the most sensible equilibrium. We find that, under certain conditions, signaling reversal may occur, i.e., the profit of the duopoly firms may be higher than that in complete information.