This paper reviews the literature on optimal income taxation with single and couple households. In the seminal works of Mirrlees and Atkinson and Stiglitz the household is composed by one member. However, I described a model where households can have more than one member. There is an economy which is composed by both one-member and two member families. This structure introduces vertical and horizontal equity considerations. For linear taxation the results of Sheshinski hold, however in optimal income taxation additional results to those of Mirrlees should be considered.
