The inefficiencies related to endogenous product creation and variety under monopolistic competition are two-fold: one static--the misalignment between consumers and producers regarding the value of a new variety; and one dynamic--time variation in markups. Quantitatively, the welfare costs of...

The inefficiencies related to endogenous product creation and variety under monopolistic competition are two-fold: one static—the misalignment between consumers and producers regarding the value of a new variety; and one dynamic—time variation in markups. Quantitatively, the welfare costs of...