The future is inherently uncertain. Key drivers of demand for infrastructure, e.g. rates of population and economic growth and changes in the climate, as well as our means of responding to change, e.g. new technologies, may evolve in a manner that is different from our current expectations.
This does not mean that attempts cannot or should not be made to make projections of the future environment which will be affected by our infrastructure decisions today. Each time decisions with long-term implications are taken, whether they are infrastructure-related or otherwise, the parties making those decisions cannot avoid taking a view about the future.
The projections underpinning the Audit's economic analysis represent a set of views about the future. The economic analysis provided two scenarios driven by different views about the rate of population growth in Australia and a third scenario which tested, at a high level, the potential implications of decisions aimed at improving the productivity of the infrastructure sectors.
In preparing the Audit, Infrastructure Australia recognises that other factors may bear on Australia's development. Equally, it is recognised that different assumptions about factors such as population growth could lead to different conclusions. Depending on how these factors 'play out', they may:
■ change the demand for infrastructure;
■ change what we need from our infrastructure; and in turn
■ influence judgments about the most appropriate infrastructure response.
That said, the factors and assumptions used in the economic analysis represent a plausible view about the future that is broadly consistent with the views of Australian governments and other organisations.