After months of crises and brinkmanship, a Grexit (a Greek euro exit) seems to stagger from week to week, with the tottering Greek banks having been kept alive by a drip feed of support from the European Central Bank (ECB), which now totals around €83 billion.

That life support is now in doubt. In the absence of a climbdown by the other eurozone governments and especially Germany, Sunday's 61 per cent vote against further austerity makes it even more likely that Greece will leave the euro.

But how can a small Mediterranean country, representing only a couple of per cent of the eurozone's GDP, have such a disproportionate effect on the world's largest trading bloc? And, what does a Grexit matter for Scotland anyway; and even if it did, what can we do about it?

When it comes to fiscal instability, Greece has some history. Between 1826 and 1932 the country defaulted five times on its sovereign debt and that puts the current difficulties into perspective.

With Greek finances becoming increasingly precarious since at least 2010, the crisis has intensified recently to the point where the lights literally went out at one tax collection office when the local government could no longer afford to pay for the electricity. And there are indications that the Greek government is becoming unable to pay for the maintenance of law and order and the provision of medicines for its hospitals.

Assuming the ECB continues drip-feeding Greek banks to maintain some measure of investor confidence, the Athens government may nevertheless face its toughest decision this summer. Should it use what is left of its diminishing revenues to pay Greek public sector workers, or repay part of the historic loans to international creditors (the so-called "Troika" of the European Commission, ECB and the International Monetary Fund, or IMF)?

What it probably can't afford is to do both. And on July 20, the latest test will come with Greece due to repay €3.5bn to the ECB.

Compounding the problem is that the Troika and the rest of the eurozone remain unconvinced that the Greek government is willing to accept a sufficiently rigorous economic reform agenda that would unlock further bail-out funding.

But, if the Greek government fails to pay the international loans then technically it will have defaulted. If that happens, could Greece then be forced to leave the euro and how much does this matter to the Scottish economy?

In a direct sense, not a lot. In 2013 Scotland sold £175 million of manufacturing exports to Greece out of total manufacturing sales of just over £27.9bn - or around 0.6 per cent. For every pound of Scottish manufacturing output, only about one-twentieth of one pence went to Greece. So, the Greek market itself is negligible.

However, what will be critical is what could happen to the rest of the eurozone, and especially the highly indebted Mediterranean economies of Portugal, Italy and Spain in the aftermath of any "Grexit". In 2014, Scottish manufacturing export sales to the Republic of Ireland, for example, totalled £920m and sales to the rest of the EU came to £12.9bn - that's almost the same as the value of exports to the rest of the world beyond the eurozone.

Of course, manufacturing exports are only one part, albeit an important part, of total trade activity. It is true that the rest of the eurozone is in better shape than in 2010 to weather the storm of any Grexit. There has been a slow recovery of output and the ECB has begun quantitative easing. That all said, Portugal and Italy are like Greece in having debt to GDP ratios that have remained stubbornly high.

It does, however, highlight the fact that anything that knocks the eurozone economies off course actually does matter to us. This point was confirmed by modelling exercises that were attempted by Fraser of Allander for Scotland in 2011 and 2012. These suggested that a Grexit, even without allowing for eurozone or global contagion, could knock about one per cent off Scottish GDP. If that's the case, a Grexit would in the short and medium term be a Greek tragedy, not just for the people of Greece, but for the rest on the eurozone, the UK and Scotland too.

Dr Birnie is PwC's chief economist in Scotland and Northern Ireland.