Taxing incumbent monopoly to foster entry

This paper investigates whether it is welfare enhancing to tax the output of a monopoly in order to foster cost-inefficient entry. This question is of particular concern in the energy markets dominated by cartel-like affiliations (OPEC and oil, Russia's gas exports to Europe) and the interest and practice to stimulate the development of alternative fuels. Making the realistic assumption that none of the players can commit to future policies, subsidies are not a viable strategy for the government. A tax cannot be first best but can be second best if the government cannot force the incumbent monopoly to sell its output at no profit and if the incumbent's profit is discounted. However, stimulating supply by improving the conditions for entry is not the prime concern of taxation (after all it lowers aggregate supplies and may even lower the entrant's supply) but to accrue parts of the monopoly rent.