Though it is generally believed that increasing competition improves social welfare, we are able to show with a Shubik–Levitan demand function for differentiated goods that this is not always the case. Under Cournot and Bertrand competition, market entry increases the equilibrium total output...

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...