The paper provides an extension and a new proof of Deaton's theorem on the undesirability of nonuniform excise taxation when income taxes are affine and preferences over consumption goods are separable from labour-leisure choices, homothetic, and identical across agents.

The paper provides an extension and a new proof of Deaton's theorem on the undesirability of nonuniform excise taxation when income taxes are affine and preferences over consumption goods are separable from labour-leisure choices, homothetic, and identical across agents.