Leader: Details must come before a decision on independence

THE Scotsman retains an open mind as to the number of options that might appear on the independence referendum ballot paper. The clarity of a single yes/no question is appealing; Mr Salmond’s manoeuvring to divide the Unionist camp with a “devo-max” option is only too transparent.

Yet there is a powerful argument for letting Scottish voters decide for themselves among competing constitutional options. Not only is that democratic, but it might also resolve the constitutional question for a generation and let the nation move on.

But whether or not there should be a second question on the ballot paper cannot be definitively answered until there is greater clarity over what devo-max actually means. The consensus is that maximal devolution implies the transfer of tax-raising powers to Holyrood, with Scotland paying into the Treasury for common UK services. Such a model is found, albeit on a small scale, in the Isle of Man. It is also used in Spain, in the Basque country.

This arrangement would force Scottish electors to link public spending gain with the with taxpayer’s pain. It would reduce friction with English voters who – rightly or wrongly – think they subsidise Scotland, and thereby strengthen the Union.

However, it is far from clear how to allocate tax-raising powers to Holyrood. In a multi-question referendum, a lack of clarity will confuse voters and unfairly profit Mr Salmond if Unionists fall out over the meaning in the midst of the campaign.

Income tax is comparatively easy to devolve, as are most taxes collected at geographical source. An obvious difficulty arises with corporation tax if it leads to competitive regional tax jurisdictions. However, many federal states live with this problem, to the benefit of business all round. VAT is more complicated because EU rules do not allow this to be set at a regional level. That can be worked around by apportioning revenues according to some agreed formula and letting Scotland (and other regions) have a voice in setting the UK VAT rate.

The really thorny question involves North Sea oil and gas. It is impossible to imagine the UK Treasury giving Holyrood control over strategic petroleum revenues. Besides, to do so would create such a political imbalance it would destabilise the UK. Equally, the SNP will not rest until Holyrood controls the oil and may denounce devo-max as a “sham” if it is not included.

Nevertheless, opinion polls do indicate majority support for some sort of devo-max option, though only by counting the second preferences of pro-independence voters. Constitutional stability would therefore depend on how willing are independence voters to settle for devo-max rather than use it as a half-way house. And that, in turn, brings us back to the practicality of the model of fiscal autonomy chosen. On that point, we need definite answers from civic Scotland and those Unionist politicians who support the idea.