Income concentration and market demand
分析了收入集中度和收入分散对市场需求及其弹性的影响，发现收入向中间集中时，服务中等收入消费者的企业面临的需求增加，价格弹性上升，市场竞争加剧。
We analyze the effects of income concentration and income dispersion on market demand and its elasticity. We show that, following an increase in income concentration towards the middle (measured by variations in mean preserving spread), the increase in demand faced by firms which serve at the margin middle income consumers, is associated with an increase in price elasticity—accordingly, the positive effects of the size of the market becoming wider are amplified by a higher degree of competition. Our results hold for a large number of possible income distributions.