Just to be clear on this - Australia is primarily interested in methods of reducing trade barriers, not any sort of political union.

Australia is economically served well by free trade: most of its production is low cost, high quality primary production of mining outputs and agricultural goods (grains, wool and meat) where if price and quality are the primary selection criteria it wins.

The downside of this is that Australia hasn't really got any significant manufacturing or advanced technology industry.

But it has made Australia one of the best performing economies of the past 25 years.