Beneath the time-honoured spats about passports, border patrols and just how many frigates make a navy, it's the economy that really counts.
Would we be the new China or the next Greece?
A recent survey found voters would overwhelmingly back independence if it made them £500 a year richer but shun it if it made them £500 poorer. So it's no surprise that much of the debate so far has been around economic matters.
Indeed, it's always been a key plank of the SNP case that an independent Scotland would be better off, as it would make its own tax and spending decisions to promote Scottish growth, rather than limp along as a Treasury afterthought.
An independent Scotland would also get 90% of North Sea oil and gas revenue, the SNP say.
But right now it's the Unionists in full cry.
"I like the pound, I like to see the Queen on it," Scots Tory leader Ruth Davidson was heard joking to an SNP MSP in the Holyrood canteen this week.
But it is not for sentimental or patriotic reasons the Unionist parties are pursuing the subject.
They know which voters' buttons to push: the ones marked fear and money.
So in the din of First Minister's Questions and in quieter briefings at Westminster, the SNP's rivals have been questioning Alex Salmond's plans for the economy and currency post-independence.
The First Minister says Scotland would keep the pound and stay in the sterling currency union, with the Bank of England setting interest rates.
His opponents tease him by saying it is a queer kind of independent country that hands control of interest rates to someone else's bank, though that's what the 17 countries in the eurozone did.
More pointedly, his critics ask what would happen in the event of a Scottish financial crisis, invariably citing the downfall of RBS and HBoS.
Who would keep struggling Scottish banks afloat?
Salmond says the Bank of England would act as their lender of last resort ... but why would it or why should it?
"What could be more ludicrous than an independent Scotland where the reserve bank is in a foreign country?" said ex-Labour chancellor, Alistair Darling.
Former LibDem leader Sir Menzies Campbell added: "What on earth would persuade the Bank of England to be the lender of last resort for an independent government?
"You can't have your cake and eat it."
However, away from the naked politics, the consensus among academics and economists (at least those who don't believe an independent Scotland would be frogmarched into the euro) seems to be that currency union with sterling would indeed be possible, in which case the Bank of England could indeed be lender of last resort to Scottish banks.
Emeritus Professor Brian Ashcroft of Strathclyde University's economics department says both are "perfectly feasible", but at a price: controls on Scotland's fiscal (tax and spending) policy.
No monetary union can tolerate a delinquent member who borrows recklessly and risks the stability of the whole group. That's what Greece did and look at the eurozone.
At the moment, Scotland doesn't have the option of misbehaving because it can't borrow more than £500 million a year, and only then in an emergency.
But if it were independent, it would inherit some of the national debt and run a deficit, issue bonds and could borrow big, and the Bank of England would want to keep a close eye on that debt in case it got out of control.
Ashcroft said: "Quite clearly the degree to which Scotland would have fiscal autonomy within that arrangement would be limited by the desire of the Bank of England to have stability across the whole monetary union. It would not want Scotland to do a Greece. So it would ask for certain requirements on debt and on deficit to GDP ratio."
In that situation it would make sense for the Bank of England to act as lender of last resort to Scottish banks in trouble because letting them fail could rebound on sterling.
"I see no reason why it wouldn't lend to Scottish banks. If they didn't do that, that would be politics," added Ashcroft.
Professor Sir Donald MacKay, a former chair of Scottish Enterprise and an economic adviser to Scottish Secretaries for 25 years, said Scotland would need to agree with the rest of the UK on the overall fiscal policy north of the Border.
"There's no question that if a Scottish Government said, 'We're not going to bother about what happens to the rest of the sterling area', then it can't be part of the sterling area.
"It's quite simple. If you want to be part of sterling you have to play by the rules.
"You could not have a Scottish Government running around behaving like a Greek government. You would have to have a sensible fiscal policy."
He suggested a new Scottish central bank could be set up to oversee public debt levels, with the Bank of England continuing to set monetary policy and interest rates.
All that means lots of negotiations ahead, with the Bank of England, and lurking behind it the Treasury, setting pre-conditions for Scotland's membership of the sterling currency union. The SNP will no doubt complain, but even Salmond has grudgingly admitted that he would have to "negotiate a stability pact" of some sort.
So how would that work? International protocols? A handy book of rules? In fact, the two sides would pretty much need to make it up as they went along.
Andrew Campbell, Professor of International Banking and Finance Law at Leeds University, said: "There is no legal framework saying exactly what should be done [if a state secedes] so it would have to be done by treaty between Scotland and the rest of the UK. If Scotland is going to get the benefit of having the Bank of England as lender of last resort then it's going to come with conditions attached and those could go as far as telling Scottish institutions how to behave."
Salmond's customary swagger wouldn't be much use in such negotiations; the fine print would be key.
George Walker, professor of Financial Regulation and Policy at Glasgow University Law School, said: "There's a lot of difficult issues, quite technical problems, and unless Edinburgh can stay very close to the Treasury and Bank of England in particular, why is London going to want to help us? There's no incentive for them to help us.
"In the absence of a separate treaty obligation the Bank of England would be under no obligation to support Scottish banks and would only provide lender of last resort to English banks, unless there was a contagious effect within the UK financial system.
"Ultimately it's going to have to be a political negotiation."
Economist John Kay, a former member of Salmond's Council of Economic Advisers, said the Bank of England would principally want to constrain Scotland's deficit, but such fiscal discipline was now expected of every country.
"It would be a bit of a straitjacket. The fact that you would have to engage in Britain-wide discussions on your fiscal policy is constraining.
"But there's a pretence at the moment that Scotland could decide all of these things unilaterally if it was independent – it couldn't.
"There are limitations on the independence of a small country in a global economy. Independence does not have the meaning it once did."
So in return for monetary union and lender of last resort security, the Bank of England would curb Scotland's fiscal policy, primarily the size of its deficit and what it used the borrowing for.
Scotland would have to agree to limit its debt and, as much as possible, borrow to invest in long-term projects which would help the economy, not fund short-term tax cuts, for example.
It wouldn't amount to a veto over the Scottish budget – how Edinburgh prioritised its spending between different departments and set taxes – but it would constrain the overall spending envelope.
However, if Scotland were one day to join the euro with the European Central Bank as lender of last resort there would be similar pre-conditions.
It is simply the way of the world.
The alternative would be to jump in the shark tank: create a new Scottish currency and throw ourselves fully on the mercy of the bond markets.
As to whether Scotland would be better or worse off, there's no cast-iron way to say.
Those who confidently foretell disaster and those who think independence guarantees nirvana are equally wrong, says Prof Sir Donald MacKay.
"Both these arguments are just nonsense," he says.
"What would happen would depend on what policies we followed. The notion you couldn't do it is absurd, and the notion that it would definitely produce good results is also absurd.
"It depends what you do with it. Scots will have to make their own judgment."
Can a small country survive in a global economy?
THE bottom line
BY tom gordon
