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α: calibrated so average coauthorship-adjusted count equals average raw count
We investigate second-best optimal taxation of the polluting variety of a product in a Bertrand duopoly with differentiated varieties. The analysis provides novel insight on a useful social function of environmental regulation. Besides internalizing the environmental externality, the taxation of the polluting variety improves the matching of consumers and product varieties, and so creates a socially desirable business switching between the differentiated varieties.