The big ''known unknown'' facing the economy is how long commodity prices and the Aussie dollar will stay so high. That's why some people worry so much about the Chinese economy coming unstuck.
But while the new secretary of the Treasury, Dr Martin Parkinson, acknowledges the risks facing China's economy, his ''central scenario'' is that commodity prices and the Aussie will stay high for a long time.
This means that, though he declined to actually say the words in his speech to the Australian Business Economists in Sydney this week, he's no believer in ''Dutch disease'' - the idea that resources booms lead to a high exchange rate, which wipes out other export and import-competing industries before the boom collapses and leaves you high and dry.
No, Parkinson has a tough message for manufacturers and others asking for assistance to help them cope with the excruciatingly high dollar: get used to it. Adapt.
There are risks facing the Chinese economy, but they are short-term risks around a positive long-term outlook. ''Our central scenario, outlined in the budget, is one of solid medium-term growth for Australia,'' he said, fuelled by high commodity prices and a mining construction boom.
The global economy is undergoing a transformation unprecedented in the last 100 years. Global strategic and economic weight is moving inexorably from the Western advanced economies towards the emerging market economies. And the pace of this transformation is faster than many expected.
The key emerging markets from our perspective are China and India, which together account for slightly more than a third of the world's population. They're growing rapidly and should continue to do so. China should overtake the United States to become the world's largest economy by 2016 and, in turn, be overtaken by India by mid-century.
''There is nothing pre-ordained about these growth paths, and size does not automatically confer economic or strategic weight,'' Parkinson said. ''But these transitions - whether smooth or rocky - have important implications for Australia. Indeed, they constitute probably the most significant external shock Australia has ever experienced.''
Urbanisation and industrialisation in China and India have resulted in strong demand for our energy and mineral resources. The resulting improved terms of trade have increased our real income as the purchasing power of our exports increased.
Looking ahead, a growing Asian middle class will boost demand for our commodities, and for our services exports - education, tourism and professional services - and for niche, high-end manufactures.
But these developments expose our economy to increased macro-economic volatility and, more importantly, to a difficult adjustment process. That's Parkinson's point: it's not just China and India that are economies in transition, it's us, too.
Our terms of trade are now at 140-year highs and the budget assumes they fall back only slowly, by about 20 per cent over 15 years. As for the Aussie dollar, it can be expected to move roughly in line with the terms of trade over the longer term. It's therefore expected to also remain persistently high.
''The implications of a sustained increase in the terms of trade and a persistently high exchange rate are significantly different to those of a temporary shock - particularly for the structure of the economy,'' Parkinson said.
Most Australian businesses are well equipped to deal with short-term exchange rate volatility, but this sustained shift ''will challenge a number of existing business models''.
''Inevitably, this will see calls for support for producers that are suffering from a lack of competitiveness due to a 'temporarily' high exchange rate,'' he said, before going on to explain why such calls should be resisted.
Higher resource prices will see capital and labour shift towards the mining sector, where they are more valuable. This shift will be facilitated by the appreciation of the exchange rate, which shifts domestic demand towards imports and reduces the competitiveness of exports and import-competing activities.
Manufacturing and other trade-exposed sectors that aren't benefiting from higher commodity prices will come under particular pressure, but all sectors will be affected. The longer-term shift away from parts of the traditional manufacturing sector, which began in the middle of the last century, will continue - though it would be wrong to assume all manufacturing will be adversely affected.
And while mining and related sectors (including the mining-related part of manufacturing) can be expected to continue to grow - drawing resources from the rest of the economy - they will be overshadowed by the longer-term shift towards the services sector.
This change to our economy - its structural evolution - reflects a prolonged shift in our comparative advantage that began in the second half of last century, as rapidly industrialising Asian countries emerged as labour-abundant (read cheap-labour) competitors.
The latest phase in this evolution is raising understandable concerns in people's minds: how are the benefits of the boom shared throughout the community? Will our manufacturing sector be ''hollowed out'' and ''lost forever'' leaving us as ''nothing but a quarry''? What if the boom suddenly stops, as all previous booms have?
''Concerns like these are being reflected in calls for measures to protect sectors threatened by the structural shift in our terms of trade,'' Parkinson said. ''They drive calls for strengthening anti-dumping legislation, intervention to deliver a lower exchange rate and increased industry assistance.''
Why is there so much discomfort in the community about this transformation? Because it involves change and change is often difficult. Because the short-term costs of adjustment are concentrated in particular sectors. But also because what's happening - the longer-term structural nature of the change - is not well understood.
People need to be reminded, for instance, that a higher exchange rate helps spread the benefits of the resources boom through the community by reducing the price of imported goods and services.
They need to be reminded the economy is always changing - far more than we realise. Each year, about 300,000 businesses are born and a similar number die. About 2 million workers start new jobs and a similar number leave their jobs. And about 500,000 workers a year change industries.
The gravity point of world trade is shifting closer to us, giving us the opportunity to become a lot richer.
''However, if we are to take advantage of these opportunities it is likely to require more change in the structure [of the economy] and, perhaps more importantly, in the mindset of Australian businesses and the skill sets of Australian workers.''
