Behind China's recent 6.9 per cent growth in GDP lies a bigger fact: between 2009 and 2030, the country will add 850 million to its middle class. I would call that a killer fact.

Nothing else on Canberra's agenda – talk about innovation, relations with India or tax cuts for business – competes with that statistic for its potential impact on Australian living standards. It is equivalent to a new continent emerging somewhere to Australia's north with 850 million more consumers asking Australia to fill its supermarkets, sell them places in our schools and universities, invest our expertise in aged and health care and let them come as tourists, investors and cashed-up migrants.

A killer fact that sweet deserves to be interrogated. To what extent can we trust it?

It was presented in a 2010 OECD working paper by Dr Homi Kharas, now co-director in the Global Economy and Development program at the Brookings Institution. His prediction was that by 2030 Europe would add only 16 million to its middle class. Small stuff, and North America's middle class was set to shrink by 16 million. In this context, 850 million more middle-class Chinese dominate world economic prospects. That means the Chinese middle class will grow from 12 per cent of its population in 2009 to 73 per cent in 2030. By middle class, Kharas means household income equivalent to between $US16,000 ($20,254) and $US160,000 per year, a widely used definition.