Profit Taxes and the Growth of Fringe Firms

In this paper we examine the optimal taxation of corporate profits in a multi-period limit pricing model where a dominant firm faces expansion by a competitive fringe. The optimal policy requires tax rates to vary both intertemporally and across firm sizes, and balances the benefit of fringe growth in eroding the market power of the dominant firm and the cost of displacing the dominant firm's output with the higher cost output of the fringe. The results are relevant for assessing the policy of giving preferential tax treatment to small firms, as practised by several OECD countries.