Not that most Australians would know, or care much.

Respected Financial Times economics columnist Martin Wolf was in Sydney last week and spoke at the Lowy Institute. He said it was a mark of Australia's maturity that it was able to largely ignore "the idiocies of an ageing and rattled parent".

It has been a long time since Australia looked to Britain for our economic future. But the 28 member states of the EU – of which Britain is one – remain our largest source of foreign direct investment and our second largest trading partner, after China. The European Union is as large an economy as the US.

Australia has been held hostage, as has the rest of the world, to Europe's periodic fiscal and currency crises since the global financial crisis.

So it is not entirely possible, or prudent, to ignore the prospect that the UK will spark another crisis if it votes to leave the European Union in a referendum to be held on June 23.

There are two things to know about the Brexit.

One, it is unlikely to happen.

While the polls are close, UK bookmakers William Hill and Ladbrokes are now paying out just one pound of profit for every six wagered on a Brexit, reflecting about an 80 per cent chance of a "Remain" vote, up from about 70 per cent a month ago.

Two, if Brexit did happen, it would have far-reaching consequences.

Europe's unprecedented migrant crisis has put enormous political strain on its policy of open borders. Meanwhile, economic stagnation in many member states has inflamed all the usual protectionist sentiments.

Advocates of "Brexit" say it's time for UK to turn its back on the moribund and inefficient economies of Europe and look increasingly to the United States and Asia.

The movement was dealt a blow when US President Barack Obama made it clear on a recent trip to the UK that it will not be treated with open arms by the world's largest economy if it decides to detonate the next biggest economy, the EU.

Brexiteers could soon find that American interest in the UK has more to do with its proximity to Europe than its own vibrant economy. The US would have less reason to do business in London if it no longer served as a gateway to Europe.

But self-inflicted wounds aside, the biggest potential for worldwide ramifications from a Brexit is the potential for it to create a ripple effect.

No country has ever withdrawn from the EU.

Sure, Britain has always stood somewhat aside, retaining its own currency. So perhaps it would not be missed much, or seen as a precedent.

But a UK "Brexit" would sure rattle an uneasy union, which has always been an unlikely triumph of political goodwill over economic self-interest. Surrendering the right to an independent currency has had a crippling effect on some weaker economies, which have been unable to enjoy the benefits of a lower currency.

If Brexit were to lead to a long-feared Grexit, then what next? A Frexit? The potential for proliferation of portmanteaus combining the world "exit" is worrying indeed.

"It would destabilise the European Union," warns the FT's Wolf of a Brexit. This would, in turn, weaken the extended western world, he adds.

Australia, which remains part of that western world as much as we court our Asian neighbours, would eventually suffer too, says Wolf, although the extent is unclear.

An unravelling of the EU could make the US look more to Asia, extending its longstanding "pivot". That might mean a more aggressive competitor for Australian exports in the region, or an expansion of overall trade to the region, of which we could grab a larger slice.

Overall, Wolf says we might ultimately view a Brexit, in the unlikely event that it happens, with "some mild regret".

One to watch.