Considering a vertical structure with perfectly competitive upstream firms that deliver a homogenous good to a differentiated retail duopoly, we show that upstream fixed costs may help to monopolize the downstream market. We find that downstream prices increase in upstream firms' fixed costs...

This paper shows that the welfare dominance of ad valorem over unit taxes under imperfect competition, extends to the Dixit-Stiglitz framework with differentiated products, entry and love of variety. This contrasts against findings by Anderson et al. (J Public Econ, 2001) made in a similar...

Environmental policies frequently target the ratio of dirty to green output within the same industry. To achieve such targets the green sector may be subsidised or the dirty sector be taxed. This paper shows that in a monopolistic competition setting the two policy instruments have different...