A Comment on a Model of Vertical Product Differentiation
评论了一个双寡头垂直差异化模型，指出当市场未被完全覆盖时，低质量企业的质量水平恰好是高质量企业的4/7，价格是2/7。
In a duopoly model with vertical differentiation, if the firms do not cover the market, the lower-quality firm chooses a quality level exactly 4/7 of that of the higher-quality firm and chooses a price that is 2/7 of the price of the higher-quality firm. Copyright 1992 by Blackwell Publishing Ltd.