This paper deals with the issue of the choice of the tax unit and the treatment of family income as emerged at the time of the introduction of the personal income tax in Italy in the Seventies. It is argued that great uncertainty involved this choice, both before and after the decision of the Constitutional Court in 1976, which stated the illegitimacy of the taxation of total family income. Basically, the necessary link between three fundamental parameters of the personal income tax - the extension of the tax base, the degree of progressivity and the choice of the tax unit - was never fully accomplished neither before nor after 1976, leaving the treatment of the family income still as an incomplete issue.
Keywords: Family income, tax unit, personal income tax, CSRT
Jel Code: H240, H000