From reading the text of the Smith agreement, it seems to me that we have handed over income tax in particular to the Scottish Government, whereby allowances and bands can be varied. In fact, we have created the possibility of an independent tax system, apart from hanging on to the 20p tax as a kind of fulcrum around which it must work. Has the Treasury looked at the impact that there would be on the UK if there were an entirely independent tax system in the north of the United Kingdom?