過去認為賣家評價對於價格是正、統計上顯著地影響價格，但是這影響卻不大，我們建立一個模型去解釋是兩種正負關係互相抵消，造成觀察到的結果是很小的情況。具體的說，賣家需要高評價分數去銷售高單價商品，而累積評價分數快速又低成本的方法就是利用低單價商品，利用降低低單價商品價格，讓銷售量增加的更快，銷售量增加快，評價就會增加快速。所以評價對於低價商品是一種負的關係，對於高單價商品才是正的關係。

It has been recognized empirically that in internet auctions, seller's reputation has a positive, statistically significant, but small impact on the price. We construct a model on internet auctions and delineate this small impact with two opposite forces. To be specific, it needs higher reputation for sellers to sell high-price goods and a cheap way to achieve this objective is to lower the price of low-price goods. By this way one can raise the sale volume of low-price commodities to increase reputation score quickly, which benefits the sale of high-price goods. Therefore, reputation imposes positive impact on prices of "expensive" goods and negative impact on prices of "cheap" ones.

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