Indirect taxes contribute to a sizeable part of government revenues around the world. Typically there are few different tax rates, and the goods are partitioned into classes associated with each rate. The present paper studies how to group the goods in these few classes. We take as given the...

In a second best environment, the optimal policy choice sometimes follows first best rules. This paper presents a formal general argument which allows to unify much of the literature. It lays down the information structure and separability assumptions under which the results hold in a variety of...