The paper considers a discrete continuous model where consumers choose quality of the product they buy as well as its usage. The product has two quality dimensions, intrinsic quality and environmental quality, that are in conflict with each other. It analyzes a two-stage game in a vertically differentiated duopoly market, where firms choose intrinsic quality in the first stage, and compete in prices in the second stage. It examines the effects of green network, and environmental regulation in the form of an emission tax on equilibrium qualities, market share, and total emissions. It shows that while both green network effect and environmental regulation, individually, improve the overall environmental quality, the effect is stronger when the tax is imposed in the presence of green network effect. Though an increase in green network effect reduces environmental quality of both firms, the market share of the cleaner firm rises at the expense of the other firm, resulting in an overall improvement of the environment. In the presence of green network effect, an emission tax improves environmental quality of both firms with market shares unaltered, thereby resulting in a reduction in total emissions. The green network effect enhances the effect of an emission tax. We also find that the environmental friendly firm benefits from the green network effect. The optimal tax is increasing in the network effect.

该论文考虑了一个离散连续模型，消费者可以在该模型中选择他们购买的产品的质量及其使用情况。产品具有相互冲突的两个质量维度，即内在质量和环境质量。它分析了垂直分化的双头垄断市场中的两阶段博弈，企业在第一阶段选择内在质量，在第二阶段进行价格竞争。它研究了绿色网络和环境监管以排放税的形式对平衡质量、市场份额和总排放量的影响。研究表明，虽然绿色网络效应和环境规制都各自改善了整体环境质量，但在绿色网络效应存在的情况下征税的效果更强。虽然绿色网络效应的增加降低了两家企业的环境质量，但清洁企业的市场份额上升以牺牲另一家企业为代价，从而导致环境的整体改善。在存在绿色网络效应的情况下，排放税改善了市场份额不变的两家公司的环境质量，从而减少了总排放量。绿色网络效应增强了排放税的效果。我们还发现，环保企业受益于绿色网络效应。最优税收在网络效应中增加。排放税在市场份额不变的情况下改善了两家公司的环境质量，从而减少了总排放量。绿色网络效应增强了排放税的效果。我们还发现，环保企业受益于绿色网络效应。最优税收在网络效应中增加。排放税在市场份额不变的情况下改善了两家公司的环境质量，从而减少了总排放量。绿色网络效应增强了排放税的效果。我们还发现，环保企业受益于绿色网络效应。最优税收在网络效应中增加。