47It must be noted in that regard that, under Article 24(2)(1) of the Convention, modelled on Article 23A(1) and (3) of the OECD Model Convention (exemption with maintenance of progressivity), income received in a State in which the taxpayer pursues an economic activity but does not reside is taxable exclusively in that State and exempt in the State of residence. The State in which the taxpayer resides may nevertheless take that income into account in calculating the amount of tax on the remaining income in order, inter alia, to apply the rule of progressivity.