Melbourne's unprecedented population growth is masking nearly a decade of stagnation in the Victorian economy, which has seen living standards fall in four of the eight years since the global financial crisis.

An investigation by The Age has detailed the extent to which Melbourne and the state are being reshaped by a booming population that has seen the city grow by nearly a million people since 2006.

Andrews government insiders were rattled by census figures released this week showing record population growth in Victoria of 146,600 people – smashing budget forecasts by at least 20,000 people. This is expected to force changes to forecasts on spending on infrastructure and other services.

If it maintained its current growth rates, Melbourne would have a population of more than 10 million by the middle of the century – well in excess of current government forecast of 8 million.