Chris

You're asking the wrong question.

It can be made to work, even if it is badly designed - spend a few minutes pondering the Eurozone. That shared currency is being kept afloat at the cost of billions of Euros the taxpayers of Germany haven't yet realised they are unable ever to get back, and at the cost of terrifying levels of unemployment that have destroyed the Greek economy for a generation.

Where the Euro project went wrong was at the very outset, when the federalist founders thought they could implement monetary union while leaving fiscal union for some later date. They knew that fiscal union would be required, in fact desirable in its own right, at some future point, but didn't push for it because the political will for it wasn't there. They didn't foresee the financial shock that has almost ripped the currency union apart (and may yet do so).

Sharing a currency is not simply a matter of agreeing to use the same tokens when purchasing goods. A modern currency is a government's principal means of economic control. Its value is determined by the strength of its economy and the trustworthiness of its government. The Euro blew up because different countries, with different tax and spending policies, caused imbalances in the system. In short, lots of Euros ended up in Germany and there were next to none left in Greece. The Euro became too expensive for Greeks to be able to afford it. With its own currency, Greece could have simply printed loads more of it, devaluing the currency and making imports horribly expensive but at least keeping the domestic economy afloat.

So, to return to the point at hand: a common Sterling zone *could* work, if

1. The lessons of the Euro were heeded, resulting in
2. A common fiscal policy for rUK and Scotland, resulting in
3. None of John Swinney's extravagant promises about competitive tax rates being possible, because
4. A successful common currency zone (see: US Dollar) relies on a central governing body which can move money around the system from where there is too much, to where there is not enough, which
5. Requires the common consent of *all* involved.

Let's be absolutely clear about this, a state that does not control its own economy is not independent in any meaningful sense. The GuessNP want to *break* the currency union of the UK and then re-forge one that will of necessity be more complex because it will be managed by politicians sitting in 2 different parliaments and 2 different governments, rather than in one place as is now the case.

And, finally, the great big elephant in the room: a fiscal union with a foreign state would lead to a loss of sovereignty for the people of the rUK and the rUK government being forced to guarantee the Scottish banking system against failure. Having just had their faces slapped with a Yes vote, how likely would the voters of Enlgand, Wales and Northern Ireland be to agree to underwrite the Scottish banking system and to allow the Scottish government to influence rUK tax policy?

Not very, I submit, is the answer to that question.