Citigroup chief economist Paul Brennan published a useful note about this recently. It explains why Australian economic growth is more closely linked to US growth, despite all the talk about the importance of China.

As Brennan points out, the closer correlation between the two countries reflects their strong financial links. And right now, those links are working in Australia's favour.

''Both economies' prospects [are] being boosted by historically low interest rates, a housing recovery and rising asset prices,'' Brennan says.

This is an important point to keep in mind, particularly as Christine Lagarde, the managing director of the International Monetary Fund, keeps talking about the risks to the global recovery.

Lagarde made the point last week that the world is at a ''critical juncture'' as it emerges from the greatest financial crisis in almost 100 years.

Thankfully, the world's advanced economies are finally starting to drive the global economic recovery. That means the global recovery is becoming more balanced.

''This is good news, because for the past five years the emerging market and developing economies have been shouldering the burden of recovery, accounting for 75 per cent of the increase in global growth since 2009,'' Lagarde said.

And the US is leading the charge for growth in the advanced economies.

This is a crucial point for Australia, because this country is facing challenges of its own. Its terms of trade - that is, the ratio of export prices versus import prices - is down 17 per cent from its peak.

As a result, Australia's nominal income growth is well below what it was even before the commodity-price boom. It will likely continue to be undercut by the slowdown in Chinese growth and Australia's increased commodity supply.

So it's a very good thing that the US recovery is getting stronger: it means the US dollar will strengthen and the Australian dollar will weaken at a time when Australia's nominal income is falling.

This is important because, as Brennan points out, economists have ''medium-term concerns'' about the sustainability of China's growth model.

They believe China's ratio of household and corporate debt to gross domestic product is now above the US and Europe's at their peak. It is too credit-dependent and investment-intensive.

''[So] the combination of slowing Chinese growth, increasing commodity supply and the [recent] partial rebound in the Australian dollar … poses a challenging global backdrop for Australia,'' Brennan says.