In my earlier article on the Calman report, I suggested that the proposal of the report that national rates of income tax as fixed by the UK Parliament should be 10% lower in Scotland than in the remainder of the UK, with the Scottish government and Parliament having the power to make up that missing 10% (and more) with a Scottish income tax to whatever degree it thinks fit, was a sleight of hand with respect to Scottish nationalists.
It is worth mentioning that the same is probably true in relation to those in England or Wales who are concerned by the West Lothian Question, or more generally by constitutional issues concerning the link between taxation and representation.
One of the outcomes of the English civil war was that it finally established that no taxation could be imposed without the authority of Parliament. The King could no longer tax in reliance on the Royal Prerogative, a matter which caused great difficulties to Charles II's administration after the Restoration. This was further entrenched in the Bill of Rights 1689 following the Glorious Revolution, Article 4 of which provides "That levying money for or to the use of the Crown by pretence of prerogative, without grant of Parliament, for longer time, or in other manner than the same is or shall be granted, is illegal".
The need for a link between taxation and representation also formed one of the calls to arms of the revolutionaries in the War of American Independence. The revolutionaries objected to being subject to taxes, and in particular stamp and excise taxes, without representation within the body which fixed them, namely Parliament. In doing so they relied on the Parliamentarian cause in the Civil War that "what an English King has no right to demand, an English subject has a right to refuse" (from the case concerning the extension of Ship Money) and on the rights established by Article 4 of the Bill of Rights. In the period before the outbreak of the Revolutionary War in America, the colonists in objecting to such taxation saw themselves as asserting their rights in defence of the British constitution and the Bill of Rights, rather than acting to subvert that constitution.
The effect of the Calman proposals is that MSPs in the Scottish Parliament must set the rate of income tax for those in Scotland, with the proviso that it is not to be more than 10% below the rate set for the rest of the UK by the UK Parliament (they can set it at any amount above that rate). Since it is pretty well inconceivable that a Scottish government would want to fix a rate of income tax more than 10% below the rate applying elsewhere in the UK, this limitation could be seen as a fig leaf to justify members of the UK Parliament for Scottish constituencies continuing to have a say on the rates of income tax applying outside Scotland. Likewise, the inability of the Scottish Parliament under the proposals to change the differential between higher and lower income tax bands might also be as much to do with keeping some link to the rates of income tax fixed for elsewhere in the UK for West Lothian purposes as with a desire to save the rich in Scotland from unwelcome depredation.
In any event, under the Calman proposals there would be no link to UK rates, for stamp duty land tax, airport passenger tax, aggregates levy and landfill tax applying in Scotland.
Of course, the call of "no taxation without representation" is not necessarily synonymous with "only those representing those paying it are to determine the amount of a tax". What one can say though is that the proposal that the Scottish Parliament should set the rates of income tax, stamp duty land tax, airport passenger tax, aggregates levy and landfill tax applying in Scotland rather than the UK parliament raises constitutional issues for the UK which somewhat belies the Calman Commission's view that it does not need to consider the West Lothian question in making its recommendations, and that it only need concern itself with the position of those in Scotland.
The UK government appears to be taking the line that no referendum in Scotland is required to give effect to the Calman proposals on tax, given that there is already a power for the Scottish Parliament to vary income tax by 3% upwards or downwards so that the principle has already been established. (The original 1998 Act referendum in Scotland covered whether this since unused 3% power should be conferred or not).
However, there is cause to consider whether for constitutional reasons it would be desirable for there to be a referendum within the rest of the UK on the assymetrical taxation autonomy which is now proposed in the report.