本文利用一垂直差異化模型，討論平行輸入的發生或仿冒的出現對代理商訂價行為與利潤的影響。我們發現在給定代理商提供的服務量下，當市場同時存在代理商品與平行輸入品時，仿冒品的出現反而會使得真品代理商的訂價與利潤均提高。此一發現打破了過去討論仿冒的文獻認為仿冒一定會使正版產品的價格降低、利潤減少的結論。此外，我們也發現另一個有趣的結果，即給定代理商提供的服務量下，仿冒的出現反而會使市場的總銷售量減少。此一結論也不同於過去文獻認為競爭會使得市場總產量提高的結論。

This paper utilizes a vertical differentiation model to investigate the impact on an agent's pricing strategy and profitability when products are subject to parallel imports and counterfeiting. We show that, given the quantity of post-sale service the agent supplies, the emergence of counterfeiting could instead increase both the price and profit of genuine products as parallel imports emerge. This finding contradicts the conclusion from earlier related literature that counterfeiting would necessarily cause both the price and profit of genuine products to fall. Furthermore, given the quantity of post-sale service the agent supplies, the appearance of counterfeits will contrarily cause the total market sales to fall, which also contrasts with previous findings.