Treasurer Morrison labelled this week's surprisingly low September-quarter GDP number as a "wake-up call". What he didn't say is that it's a call that's been ringing for three years. Nobody in the government bothered to answer it.

Three years is how long mining investment has been tumbling towards the September quarter's inevitable conclusion. For those three years, the government has primarily relied on low interest rates to provide an alternative growth engine. It has turned out that the main contribution of low interest rates has been to encourage higher housing prices, which in turn has helped maintain consumer spending through the wealth effect.

No, it has never been a sustainable solution. A very valuable transition mechanism that has done a great job, yes, but you can't rely on always increasing the number of dwelling units being built and renovated. Growth through housing expansion is coming to an end.

It's by no means too late to answer that wake-up call, for the government to get serious about providing sustainable fiscal stimulus. We're not about to fall into recession this quarter – but our economic horizon is shrinking.