A two-region economy consists of a given but different number of immobile workers in each region, and a given number of mobile firms. Firms create jobs where they locate, but there is frictional unemployment. Two sorts of agglomeration effects arise: those from economies of scale in matching,...

Deaton (1979) showed that if preferences are weakly separable in goods and labour and quasihomothetic in goods and the government imposes an optimal linear progressive tax, commodity taxes are redundant. Hellwig (2009) generalized the Deaton theorem by showing that the allocation obtained under...