The paper shows how commodity taxes can provide insurance to consumers when the producer price is volatile. Specific and ad valorem taxes have differing roles. The optimal specific tax is positive when demand has some elasticity. The optimal ad valorem rate is zero when demand is unit-elastic,...

Probably the most enduring result in the theory of optimum income taxation is that,for a sufficiently thin upper tail to the skill distribution, the marginal tax rate shouldfall rather than rise with income. This paper shows that this result is highly sensitiveto a very strong informational...