Indirect taxation and undesirable competition

This paper studies undesirable competition in an asymmetric oligopoly under ad valorem taxation. We show that when the cost advantage of efficient firms is large, both the entry of and the cost reduction in efficient firms raise social welfare, but unexpectedly hurt consumers. Moreover, we find that unit taxation yields higher consumer surplus in equilibrium, and it could also be welfare superior to ad valorem taxation under certain conditions. (C) 2019 Elsevier B.V. All rights reserved.