Alex Salmond used to say the Scots would join the Euro. For a time this was a sellable proposition, but as recent events have made this less and less credible, Salmond has reverted to saying a newly independent Scotland would keep the pound.
Fine. Let's assume Westminster agrees (although it might not). Now, who will be your central bank, Alex? Would it be the Bank of England, by any chance? And when that Bank sets interest rates, will it set them according to economic data from the UK as presently constituted, or will it just take data from England, Wales and Northern Ireland?
That's a no brainer: there is no way that a post-independence Bank of England will be taking account of what's happening in Scotland. For one thing, it would be politically unacceptable in England. No, after independence, if Scotland keeps the pound, it will have interest rates determined by the Bank of England, ignoring conditions in Scotland. That means that even if Scotland doesn't have the wrong base rate from day one, it'll have the wrong rate pretty soon after. Given that England tends to have stronger growth, in practical terms it means Scotland is likely to have base rates that are too high, strangling its economy.
And if Scotland were to join the Euro, what then? For the forseeable future it's a fair bet that national budgets of Eurozone countries will have to be vetted by Brussels. What kind of independence is it which exchanges the pooling of economic sovereignty with the rest of the UK for pooled sovereignty with twenty-odd other countries across a cold stretch of sea? Countries moreover with whom one has none of the ties of geography, language, culture, history and personal affection that bind, however loosely, the UK?
No, for the Jocks it'll be the Groat, or nothing.
