Monopoly Power and Endogenous Product Variety: Distortions and Remedies
分析垄断竞争下内生产品创造和多样性的双重低效：静态上消费者与生产者对新品种价值认知错位，动态上加成率随时间变化。量化表明各扭曲单独造成2%-5%消费福利损失，但共同存在时损失放大至25%。
The inefficiencies related to endogenous product creation and variety under monopolistic competition are two-fold: one static—the mis-alignment between consumers and producers regarding the value of a new variety; and one dynamic—time variation in markups. When production factors (labor and physical capital ) are elastic and traded in competitive markets, further distortions appear. Appropriate taxation schemes can restore optimality if they preserve entry incentives. Quantitatively, the welfare costs of each distortion by itself amounts to 2 to 5 percent of consumption. But their overall cost when jointly present is greatly magnified, and generates up to a 25 percent welfare loss.